better error message for `propTypes` check

Summary:
When you did a typo in declaring a prop type (like using `boolean` insteal of `bool`) you'd got a bit misleading error message:
{F27113768}
The truth is that the prop type is defined, but not correctly. So I've changed the message in this case to be more accurate:
{F27113627}

public

Reviewed By: sahrens

Differential Revision: D2729340

fb-gh-sync-id: dd12c10a4f3a1c9825293f86481a082908127a76

Libraries/ReactIOS/verifyPropTypes.js

@@ -41,11 +41,16 @@ function verifyPropTypes(
     if (!componentInterface.propTypes[prop] &&
         !ReactNativeStyleAttributes[prop] &&
         (!nativePropsToIgnore || !nativePropsToIgnore[prop])) {
-      throw new Error(
-        '`' + componentName + '` has no propType for native prop `' +
+      var message;
+      if (componentInterface.propTypes.hasOwnProperty(prop)) {
+        message = '`' + componentName + '` has incorrectly defined propType for native prop `' +
+        viewConfig.uiViewClassName + '.' + prop + '` of native type `' + nativeProps[prop];
+      } else {
+        message = '`' + componentName + '` has no propType for native prop `' +
         viewConfig.uiViewClassName + '.' + prop + '` of native type `' +
-        nativeProps[prop] + '`'
-      );
+        nativeProps[prop] + '`';
+      };
+      throw new Error(message);
     }
   }
 }