Fix crash when PlatformColor is used as backgroundColor

Summary:
@public

When PlatformColor is used with backgroundColor, this line would throw, as the object type is not convertible to int.

Changelog:
[Android][Fixed] - Fix Crash in ViewProps.isLayoutOnly

Reviewed By: JoshuaGross

Differential Revision: D29430151

fbshipit-source-id: a1fe801925430dad3a17871bdebb79d942775280

ReactAndroid/src/main/java/com/facebook/react/uimanager/interfaces/ViewProps.java

@@ -9,6 +9,7 @@
 
 import android.graphics.Color;
 import com.facebook.react.bridge.ReadableMap;
+import com.facebook.react.bridge.ReadableType;
 import java.util.Arrays;
 import java.util.HashSet;
 
@@ -258,10 +259,14 @@ public static boolean isLayoutOnly(ReadableMap map, String prop) {
         // Ignore if explicitly set to default opacity.
         return map.isNull(OPACITY) || map.getDouble(OPACITY) == 1d;
       case BORDER_RADIUS: // Without a background color or border width set, a border won't show.
-        if (map.hasKey(BACKGROUND_COLOR)
-            && !map.isNull(BACKGROUND_COLOR)
-            && map.getInt(BACKGROUND_COLOR) != Color.TRANSPARENT) {
-          return false;
+        if (map.hasKey(BACKGROUND_COLOR)) {
+          ReadableType valueType = map.getType(BACKGROUND_COLOR);
+          if (valueType == ReadableType.Number
+              && map.getInt(BACKGROUND_COLOR) != Color.TRANSPARENT) {
+            return false;
+          } else if (valueType != ReadableType.Null) {
+            return false;
+          }
         }
         if (map.hasKey(BORDER_WIDTH)
             && !map.isNull(BORDER_WIDTH)