Merge "SoundPool: Implement generic garbage collection" am: 361e9e1da9 am: 135ebfe059 am: e6c9a5de4b am: 01a98143e3

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

Change-Id: Idf613d196626c11fbbe75e5f4ca75c97b576cb43