Integrate Flipper in RNTester on Android (#27631)

Summary:
0.62 Flipper Support items: https://github.com/facebook/react-native/issues/27565
Made RNTester's Android Flipper implementation consistent with the template.
~~Added Flipper to the iOS build.~~
<img width="1259" alt="Screen Shot 2019-12-28 at 7 06 42 PM" src="https://user-images.githubusercontent.com/8675043/71551835-37290800-29a5-11ea-9eac-b119a69a68c1.png">

## Changelog

[Internal] [Added] - RNTester Android Fipper updates
Pull Request resolved: https://github.com/facebook/react-native/pull/27631

Test Plan: Run RNTester and see if it connects to Flipper.

Reviewed By: rickhanlonii

Differential Revision: D19345093

Pulled By: passy

fbshipit-source-id: 6957c1ca3f4a5bb7f0e581c5daf8ddeac5d87eea

RNTester/android/app/build.gradle

@@ -170,15 +170,15 @@ dependencies {
     debugImplementation files(hermesPath + "hermes-debug.aar")
     releaseImplementation files(hermesPath + "hermes-release.aar")
 
-    debugImplementation("com.facebook.flipper:flipper:0.30.2") {
+    debugImplementation("com.facebook.flipper:flipper:${FLIPPER_VERSION}") {
         exclude group:'com.facebook.fbjni'
     }
 
-    debugImplementation("com.facebook.flipper:flipper-network-plugin:0.30.2") {
+    debugImplementation("com.facebook.flipper:flipper-network-plugin:${FLIPPER_VERSION}") {
         exclude group:'com.facebook.flipper'
     }
 
-    debugImplementation("com.facebook.flipper:flipper-fresco-plugin:0.30.2") {
+    debugImplementation("com.facebook.flipper:flipper-fresco-plugin:${FLIPPER_VERSION}") {
         exclude group:'com.facebook.flipper'
     }
 

RNTester/android/app/gradle.properties

@@ -7,3 +7,6 @@ MYAPP_RELEASE_KEY_PASSWORD=android
 
 android.useAndroidX=true
 android.enableJetifier=true
+
+# Version of flipper SDK to use with React Native
+FLIPPER_VERSION=0.30.2

RNTester/android/app/src/main/java/com/facebook/react/uiapp/RNTesterApplication.java

@@ -16,6 +16,7 @@ import com.facebook.react.ReactNativeHost;
 import com.facebook.react.ReactPackage;
 import com.facebook.react.shell.MainReactPackage;
 import com.facebook.react.views.text.ReactFontManager;
+import com.facebook.soloader.SoLoader;
 import java.lang.reflect.InvocationTargetException;
 import java.util.Arrays;
 import java.util.List;
@@ -48,6 +49,7 @@ public class RNTesterApplication extends Application implements ReactApplication
   public void onCreate() {
     ReactFontManager.getInstance().addCustomFont(this, "Rubik", R.font.rubik);
     super.onCreate();
+    SoLoader.init(this, /* native exopackage */ false);
     initializeFlipper(this, getReactNativeHost().getReactInstanceManager());
   }