fix memory leak

Summary:
Signed-off-by: yk3372 <yk3372@gmail.com>

What existing problem does the pull request solve?

ViewManagersPropertyCache, ViewManagerPropertyUpdater static field not release when ReactInstanceManager called destroy.

I use this url to integrate RN:
[http://facebook.github.io/react-native/docs/integration-with-existing-apps.html](http://facebook.github.io/react-native/docs/integration-with-existing-apps.html)
and in Activity's onDestroy function add the follow code to release RN:
```java
mReactInstanceManager.destroy();
mReactInstanceManager = null;
```
and then when I exit activity, find the static field not release.
the follow is screen shot:
before:
![2017-05-23 17 41 16](https://cloud.githubusercontent.com/assets/1514899/26350318/53ea250c-3fe5-11e7-8eda-a0dcc20ba4f6.jpg)
after:
![2017-05-23 17 38 49](https://cloud.githubusercontent.com/assets/1514899/26350329/5e5b273e-3fe5-11e7-9b0b-a8b0e044abf3.jpg)
Closes https://github.com/facebook/react-native/pull/14172

Differential Revision: D5128834

Pulled By: javache

fbshipit-source-id: 657763fa21fd8826b4060f9a17e7f35f0e1e04d3

ReactAndroid/src/main/java/com/facebook/react/uimanager/UIManagerModule.java

@@ -149,6 +149,7 @@ public class UIManagerModule extends ReactContextBaseJavaModule implements
 
     getReactApplicationContext().unregisterComponentCallbacks(mMemoryTrimCallback);
     YogaNodePool.get().clear();
+    ViewManagerPropertyUpdater.clear();
   }
 
   private static Map<String, Object> createConstants(

ReactAndroid/src/main/java/com/facebook/react/uimanager/ViewManagerPropertyUpdater.java

@@ -30,6 +30,12 @@ public class ViewManagerPropertyUpdater {
       new HashMap<>();
   private static final Map<Class<?>, ShadowNodeSetter<?>> SHADOW_NODE_SETTER_MAP = new HashMap<>();
 
+  public static void clear() {
+    ViewManagersPropertyCache.clear();
+    VIEW_MANAGER_SETTER_MAP.clear();
+    SHADOW_NODE_SETTER_MAP.clear();
+  }
+
   public static <T extends ViewManager, V extends View> void updateProps(
       T manager,
       V v,

ReactAndroid/src/main/java/com/facebook/react/uimanager/ViewManagersPropertyCache.java

@@ -28,6 +28,11 @@ import com.facebook.react.uimanager.annotations.ReactPropGroup;
   private static final Map<Class, Map<String, PropSetter>> CLASS_PROPS_CACHE = new HashMap<>();
   private static final Map<String, PropSetter> EMPTY_PROPS_MAP = new HashMap<>();
 
+  public static void clear() {
+    CLASS_PROPS_CACHE.clear();
+    EMPTY_PROPS_MAP.clear();
+  }
+
   /*package*/ static abstract class PropSetter {
 
     protected final String mPropName;