[automerged blank] Add caching mechanism to speed up midi file reading speed. 2p: b801c8999f

Blank merge reason: Change-Id I1db7c739a69f4324cc339b8521b5a6998e8a8df0 with SHA-1 cffbc15d58 is in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/av/+/13381942

Change-Id: I255f72ff84e3efc3d6fd1270302dd9ba8433dd9d