Merge "MP4: Use track header to get playback duration" into main am: d3dc8adf2c am: 49fb63b477

Original change: https://android-review.googlesource.com/c/platform/frameworks/av/+/3124613

Change-Id: I0b612cbabf11830251d6f8c100e320ac9e082c82
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>