Use tag ids for testID

Summary: View tags are currently used for end-to-end test IDs. We'd like to overload the tag field with other information such as nativeID (for native refs) and transitionID (for shared element transitions) in the future. Added a key for testID's tag

Reviewed By: AaaChiuuu

Differential Revision: D4833045

fbshipit-source-id: c2f9371c9a3dbb2411e114f4f096f723ac3132c0

ReactAndroid/src/androidTest/java/com/facebook/react/testing/ReactTestHelper.java

@@ -17,6 +17,7 @@ import android.view.View;
 import android.view.ViewGroup;
 
 import com.facebook.react.NativeModuleRegistryBuilder;
+import com.facebook.react.R;
 import com.facebook.react.ReactInstanceManager;
 import com.facebook.react.ReactInstanceManagerBuilder;
 import com.facebook.react.bridge.CatalystInstance;
@@ -187,7 +188,9 @@ public class ReactTestHelper {
   }
 
   public static String getTestId(View view) {
-    return view.getTag() instanceof String ? (String) view.getTag() : null;
+    return view.getTag(R.id.react_test_id) instanceof String
+      ? (String) view.getTag(R.id.react_test_id)
+      : null;
   }
 
   private static View findChild(View root, Predicate<View> predicate) {
@@ -211,7 +214,7 @@ public class ReactTestHelper {
     return new Predicate<View>() {
       @Override
       public boolean apply(View view) {
-        Object tag = view.getTag();
+        Object tag = getTestId(view);
         return tag != null && tag.equals(tagValue);
       }
     };