Merge "SoundPool: Implement generic garbage collection" am: 361e9e1da9 am: 135ebfe059 am: e6c9a5de4b

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1905392

Change-Id: If2874f4fedfa161a03e579d8093e8a490349525b