CCodec: don't trigger output format change after flush

Bug: 149751672
Test: atest CtsMediaTestCases:AdaptivePlaybackTest
Merged-In: If34bd5eba1498f081d613d2ebc15ff75f2a90f2f
Change-Id: If34bd5eba1498f081d613d2ebc15ff75f2a90f2f
2 files changed