MediaCodec: fix output format change event timing

In synchronous mode, process output format change at
dequeue, instead of at drain. Keep processing the change
at drain for asynchronous mode.

Fix redundant output format change logging.

Bug: 149751672
Test: atest CtsMediaTestCases:AdaptivePlaybackTest
Test: atest CtsMediaTestCases -- --module-arg CtsMediaTestCases:size:small
Merged-In: Ib373b71ba65f460edaf82365f8dd9be35348f635
Change-Id: Ib373b71ba65f460edaf82365f8dd9be35348f635