C2BqPool: Do not call cancelBuffer() after invalidated

Do not call IGBP::cancelBuffer() from C2BqPool based blocks after the
Pool is invalidated.

Bug: 304183768
Test: atest android.media.decoder.cts.AdaptivePlaybackTest
Change-Id: Ic03a42077c5e752722c3c7c654e03c4f6fedde4d
1 file changed