fix WritableArray, WritableMap nullable annotations (#23397)

Summary:
Recently, I added nullable annotations to ReadableArray, ReadableMap, WritableArray, WritableMap and subclasses to improve Kotlin developer experience. But found that I made mistake with pushArray, pushMap, pushString method of WritableArray, and putArray, putMap, putString methods of WritableMap. This PR fixes previous mistake.

Excerpt from WritableNativeArray.cpp.
```cpp
void WritableNativeArray::pushString(jstring value) {
  if (value == NULL) {
    pushNull();
    return;
  }
  throwIfConsumed();
  array_.push_back(wrap_alias(value)->toStdString());
}

void WritableNativeArray::pushNativeArray(WritableNativeArray* otherArray) {
  if (otherArray == NULL) {
    pushNull();
    return;
  }
  throwIfConsumed();
  array_.push_back(otherArray->consume());
}

void WritableNativeArray::pushNativeMap(WritableNativeMap* map) {
  if (map == NULL) {
    pushNull();
    return;
  }
  throwIfConsumed();
  array_.push_back(map->consume());
}
```

Excerpt from WritableNativeMap.cpp
```cpp
void WritableNativeMap::putString(std::string key, alias_ref<jstring> val) {
  if (!val) {
    putNull(std::move(key));
    return;
  }
  throwIfConsumed();
  map_.insert(std::move(key), val->toString());
}

void WritableNativeMap::putNativeArray(std::string key, WritableNativeArray* otherArray) {
  if (!otherArray) {
    putNull(std::move(key));
    return;
  }
  throwIfConsumed();
  map_.insert(key, otherArray->consume());
}

void WritableNativeMap::putNativeMap(std::string key, WritableNativeMap *otherMap) {
  if (!otherMap) {
    putNull(std::move(key));
    return;
  }
  throwIfConsumed();
  map_.insert(std::move(key), otherMap->consume());
}
```

[Android] [Changed] - fix nullable annotations in WritableArray, WritableMap
Pull Request resolved: https://github.com/facebook/react-native/pull/23397

Differential Revision: D14044014

Pulled By: cpojer

fbshipit-source-id: c44ea2e097e7b1156223b516aa640a181f0d4a9b

ReactAndroid/src/main/java/com/facebook/react/bridge/JavaOnlyArray.java

@@ -160,7 +160,7 @@ public class JavaOnlyArray implements ReadableArray, WritableArray {
   }
 
   @Override
-  public void pushString(@Nonnull String value) {
+  public void pushString(@Nullable String value) {
     mBackingList.add(value);
   }
 
@@ -170,7 +170,7 @@ public class JavaOnlyArray implements ReadableArray, WritableArray {
   }
 
   @Override
-  public void pushMap(@Nonnull WritableMap map) {
+  public void pushMap(@Nullable WritableMap map) {
     mBackingList.add(map);
   }
 

ReactAndroid/src/main/java/com/facebook/react/bridge/JavaOnlyMap.java

@@ -12,6 +12,7 @@ import java.util.Iterator;
 import java.util.Map;
 
 import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 
 /**
  * Java {@link HashMap} backed implementation of {@link ReadableMap} and {@link WritableMap}
@@ -179,7 +180,7 @@ public class JavaOnlyMap implements ReadableMap, WritableMap {
   }
 
   @Override
-  public void putString(@Nonnull String key, @Nonnull String value) {
+  public void putString(@Nonnull String key, @Nullable String value) {
     mBackingMap.put(key, value);
   }
 
@@ -189,7 +190,7 @@ public class JavaOnlyMap implements ReadableMap, WritableMap {
   }
 
   @Override
-  public void putMap(@Nonnull String key, @Nonnull WritableMap value) {
+  public void putMap(@Nonnull String key, @Nullable WritableMap value) {
     mBackingMap.put(key, value);
   }
 
@@ -199,7 +200,7 @@ public class JavaOnlyMap implements ReadableMap, WritableMap {
   }
 
   @Override
-  public void putArray(@Nonnull String key, @Nonnull WritableArray value) {
+  public void putArray(@Nonnull String key, @Nullable WritableArray value) {
     mBackingMap.put(key, value);
   }
 

ReactAndroid/src/main/java/com/facebook/react/bridge/WritableArray.java

@@ -8,6 +8,7 @@
 package com.facebook.react.bridge;
 
 import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 
 /**
  * Interface for a mutable array. Used to pass arguments from Java to JS.
@@ -18,7 +19,7 @@ public interface WritableArray extends ReadableArray {
   void pushBoolean(boolean value);
   void pushDouble(double value);
   void pushInt(int value);
-  void pushString(@Nonnull String value);
+  void pushString(@Nullable String value);
-  void pushArray(@Nonnull WritableArray array);
+  void pushArray(@Nullable WritableArray array);
-  void pushMap(@Nonnull WritableMap map);
+  void pushMap(@Nullable WritableMap map);
 }

ReactAndroid/src/main/java/com/facebook/react/bridge/WritableMap.java

@@ -8,6 +8,7 @@
 package com.facebook.react.bridge;
 
 import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 
 /**
  * Interface for a mutable map. Used to pass arguments from Java to JS.
@@ -18,9 +19,9 @@ public interface WritableMap extends ReadableMap {
   void putBoolean(@Nonnull String key, boolean value);
   void putDouble(@Nonnull String key, double value);
   void putInt(@Nonnull String key, int value);
-  void putString(@Nonnull String key, @Nonnull String value);
+  void putString(@Nonnull String key, @Nullable String value);
-  void putArray(@Nonnull String key, @Nonnull WritableArray value);
+  void putArray(@Nonnull String key, @Nullable WritableArray value);
-  void putMap(@Nonnull String key, @Nonnull WritableMap value);
+  void putMap(@Nonnull String key, @Nullable WritableMap value);
 
   void merge(@Nonnull ReadableMap source);
 }

ReactAndroid/src/main/java/com/facebook/react/bridge/WritableNativeArray.java

@@ -38,7 +38,7 @@ public class WritableNativeArray extends ReadableNativeArray implements Writable
   @Override
   public native void pushInt(int value);
   @Override
-  public native void pushString(@Nonnull String value);
+  public native void pushString(@Nullable String value);
 
   // Note: this consumes the map so do not reuse it.
   @Override
@@ -50,7 +50,7 @@ public class WritableNativeArray extends ReadableNativeArray implements Writable
 
   // Note: this consumes the map so do not reuse it.
   @Override
-  public void pushMap(@Nonnull WritableMap map) {
+  public void pushMap(@Nullable WritableMap map) {
     Assertions.assertCondition(
         map == null || map instanceof WritableNativeMap, "Illegal type provided");
     pushNativeMap((WritableNativeMap) map);

ReactAndroid/src/main/java/com/facebook/react/bridge/WritableNativeMap.java

@@ -14,6 +14,7 @@ import com.facebook.infer.annotation.Assertions;
 import com.facebook.proguard.annotations.DoNotStrip;
 
 import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 
 /**
  * Implementation of a write-only map stored in native memory. Use
@@ -33,13 +34,13 @@ public class WritableNativeMap extends ReadableNativeMap implements WritableMap
   @Override
   public native void putInt(@Nonnull String key, int value);
   @Override
-  public native void putString(@Nonnull String key, @Nonnull String value);
+  public native void putString(@Nonnull String key, @Nullable String value);
   @Override
   public native void putNull(@NonNull String key);
 
   // Note: this consumes the map so do not reuse it.
   @Override
-  public void putMap(@Nonnull String key, @Nonnull WritableMap value) {
+  public void putMap(@Nonnull String key, @Nullable WritableMap value) {
     Assertions.assertCondition(
         value == null || value instanceof WritableNativeMap, "Illegal type provided");
     putNativeMap(key, (WritableNativeMap) value);
@@ -47,7 +48,7 @@ public class WritableNativeMap extends ReadableNativeMap implements WritableMap
 
   // Note: this consumes the map so do not reuse it.
   @Override
-  public void putArray(@Nonnull String key, @Nonnull WritableArray value) {
+  public void putArray(@Nonnull String key, @Nullable WritableArray value) {
     Assertions.assertCondition(
         value == null || value instanceof WritableNativeArray, "Illegal type provided");
     putNativeArray(key, (WritableNativeArray) value);