Fix Imports in React Native template

Summary: Looks like some of the imports went missing when merging. Found this when testing this again.

Reviewed By: mdvacca

Differential Revision: D17200737

fbshipit-source-id: ded39493786d4999317c5e29be270e5990601b06

Author: axe-fb

template/android/app/src/debug/java/com/helloworld/ReactNativeFlipper.java

@@ -6,6 +6,12 @@
  */
 package com.helloworld;
 
+import android.content.Context;
+import com.facebook.flipper.android.AndroidFlipperClient;
+import com.facebook.flipper.android.utils.FlipperUtils;
+import com.facebook.flipper.core.FlipperClient;
+import com.facebook.flipper.plugins.crashreporter.CrashReporterPlugin;
+import com.facebook.flipper.plugins.databases.DatabasesFlipperPlugin;
 import com.facebook.flipper.plugins.fresco.FrescoFlipperPlugin;
 import com.facebook.flipper.plugins.inspector.DescriptorMapping;
 import com.facebook.flipper.plugins.inspector.InspectorFlipperPlugin;