MPEG4Writer:Avoid deadlock when reset internally

For client initiated request, reset's return value is important
and hence wait for any previous internal reset to complete.
For reset initiated by control looper thread, prevent multiple
simultaneous calls to avoid deadlock.
Save reset status and return the same in subsequent calls.

Bug: 159082429
Bug: 159225772

Test:   atest android.media.cts.MediaMuxerTest \
        android.mediav2.cts.MuxerTest \
        android.mediav2.cts.MuxerUnitTest \
        android.media.cts.MediaRecorderTest \
        android.mediastress.cts.MediaRecorderStressTest \
        android.mediastress.cts.MediaMuxerStressTest

Change-Id: Idda58a65abf7f49989f9aec2a7c56413ee3aebdd