Updated to Google Play Game services SDK v2

Updated Google Play Games service to SDK v2.

⚠️ ⚠️ ⚠️ Breaking changes ⚠️ ⚠️ ⚠️

• Logout function was removed because v2 doesn't support sign out functionality
• The setGravityForPopups function was removed because v2 doesn't have such functionality any more
• The getIdToken function was removed because there is no need to work with regular Google account. The only account that is used is the Google Play Games account on the device.
• The game.project setting gpgs.client_id should be the OAuth2 client id for web application. The client id is used for retrieving server auth token during login flow
• Fixed type fomatted_value -> formatted_value in event's information
• The game.project setting for Android minimum SDK version should be >= 21

Update Google Play Game Services to version 23.1.0

Dependencies were updated to the latest versions available at the moment:

play-services-base:18.3.0
play-services-auth:20.7.0
play-services-games:23.1.0

Add missing `gpgs.MSG_SAVE_SNAPSHOT` constant

• add missing gpgs.MSG_SAVE_SNAPSHOT constant

Updated to use new Lua json decoder

Works with Defold 1.4.0+

Remove `#` symbol from `game.project`

• game.project shouldn't contain # symbol if it's not an index of an array

Fix for Defold 1.2.190

• Use new dmAndroid::RegisterOnActivityResultListener API instead of dmExtension::RegisterAndroidOnActivityResultListener

Fix regression after previous commit

• Restore overwritten fix for #37

Smaller mutex scope + use new Defold SDK api

• Use smaller scope for the callbacks mutex to avoid possible ANRs/Crashes
• Use new Defold SDK API (1.2.188) for attaching VM thread and loading java class

Google Play Game Services 2.3.1

FIX: Crash when call gpgs.snapshot_commit_and_close() on armv7 Android phone.

Google Play Game Services 2.3.0

NEW: Improved error reporting back to the client. When an ApiExceptions is caught an error_status with additional information is also provided (from apiException.getStatusCode())