Adding MultiDex to Godot

As it stands enabling Firestore will result in dex overload ( > 64K methods ). to bypass this we need to implement multidex into the android application, follow this steps if you want to enable firestore.

In your GODOT/platform/android/build.gradle.template and

defaultConfig {
    ...

    // Enabling multidex support.
    multiDexEnabled true
}

and in GODOT/platform/android/java/src/org/godotengine/godot/Godot.java add the following function

    @Override
    protected void attachBaseContext(Context base) {
        super.attachBaseContext(base);
        MultiDex.install(this);
    }