Hello,
If my pixel c is set to portrait orientation and the screen is locked unlocking the screen causes the game to restart. If I set the orientation to landscape I can safely lock and unlock the tablet with no issues and the game does not restart. I found a thread about this type of issue on stackoverflow, not sure if it is the same issue or not but the behavior is the same.
http://stackoverflow.com/questions/1383 ... on-on-lock