Fix: Release builds on android (#1325)

Summary:
After `react-native-flipper` 0.48.0 I cannot build releases on android (I think that passed on CI tests because the example was running an older version of this package, 0.47.0).
So I moved all the `android/src/main` content to `android/src/debug` because we will not use Flipper in another Build Variant

## Changelog

I moved all content from `react-native-flipper/android/src/main` to `react-native-flipper/android/src/debug`.

Probably solves https://github.com/facebook/flipper/issues/1303
Pull Request resolved: https://github.com/facebook/flipper/pull/1325

Test Plan: Maybe create a custom CI script to verify if Flipper deps are present on Release Builds, [something like this](https://github.com/facebook/flipper/issues/1274#issue-641197153)

Reviewed By: cekkaewnumchai

Differential Revision: D22333432

Pulled By: passy

fbshipit-source-id: 4abbab5ecbe08d44752b2138569ff60d25724087

react-native/ReactNativeFlipperExample/android/gradle.properties

@@ -30,4 +30,4 @@ android.useAndroidX=true
 android.enableJetifier=true
 
 # Version of flipper SDK to use with React Native
-FLIPPER_VERSION=0.47.0
+FLIPPER_VERSION=0.49.0

react-native/ReactNativeFlipperExample/package.json

@@ -12,7 +12,7 @@
   "dependencies": {
     "react": "^16.13",
     "react-native": "^0.62.2",
-    "react-native-flipper": "^0.47.0"
+    "react-native-flipper": "^0.49.0"
   },
   "devDependencies": {
     "@babel/core": "^7.6.2",

react-native/react-native-flipper/android/src/debug/AndroidManifest.xml

@@ -0,0 +1,4 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
+    xmlns:tools="http://schemas.android.com/tools">
+
+</manifest>