Update to react-native 0.64 and enable Hermes

Summary:
allow-large-files

Per title. hermes enabled so that we can verify the hermes debugger works.

Reviewed By: passy

Differential Revision: D27229331

fbshipit-source-id: c2e45151b9d2097edc7e79f54eb89f9d110899d6

react-native/ReactNativeFlipperExample/android/app/build.gradle

@@ -85,7 +85,7 @@ import com.android.build.OutputFile
  */
 
 project.ext.react = [
-    enableHermes: false,  // clean and rebuild if changing
+    enableHermes: true,  // clean and rebuild if changing
 ]
 
 apply from: "../../node_modules/react-native/react.gradle"
@@ -128,6 +128,8 @@ def jscFlavor = 'org.webkit:android-jsc:+'
 def enableHermes = project.ext.react.get("enableHermes", false);
 
 android {
+    ndkVersion rootProject.ext.ndkVersion
+
     compileSdkVersion rootProject.ext.compileSdkVersion
 
     compileOptions {
@@ -180,7 +182,7 @@ android {
             def abi = output.getFilter(OutputFile.ABI)
             if (abi != null) {  // null for the universal-debug, universal-release variants
                 output.versionCodeOverride =
-                        versionCodes.get(abi) * 1048576 + defaultConfig.versionCode
+                        defaultConfig.versionCode * 1000 + versionCodes.get(abi)
             }
 
         }

react-native/ReactNativeFlipperExample/android/app/src/debug/AndroidManifest.xml

@@ -5,5 +5,10 @@
     <uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>
     <uses-permission android:name="android.permission.INTERNET" />
 
-    <application android:usesCleartextTraffic="true" tools:targetApi="28" tools:ignore="GoogleAppIndexingWarning" />
+    <application
+        android:usesCleartextTraffic="true"
+        tools:targetApi="28"
+        tools:ignore="GoogleAppIndexingWarning">
+        <activity android:name="com.facebook.react.devsupport.DevSettingsActivity" />
+    </application>
 </manifest>