Add Automotive OS API 29 stubs to platform SDK optionals. am: ecf644f2d6 am: 7737e3dc01 am: 683c5ffe37 am: d18b3d9a78

Original change: https://googleplex-android-review.googlesource.com/c/platform/development/+/12221485

Change-Id: I7dc5e1ec25d63a318f727adb4307780014e86fda