Merge "Speed up SniffMidi() by parsing the initial bytes of the header" into main am: 92949994fc am: ac14ed7bf5

Original change: https://android-review.googlesource.com/c/platform/frameworks/av/+/3286814

Change-Id: Id5d501806f88ee2a6ffdf598512d068f7e461a79
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>