AwesomePlayer: improve scheduling of video event to hit PTS

Change-Id: I7b19911acbde9b592b757b952d4ad63cd8efebed

AwesomePlayer: use PTS for queueBuffer

Change-Id: I1c14ad4784c799c46cf06a14b0f00c5e4d01f718
Fix decoder EOS handling

Conceptually it should be the same whether EOS is signalled on the last
buffer holding data, or an empty buffer that follows. Make it so that
this actually behaves the same for mp3, AAC and Vorbis.

b/8747869

Change-Id: Idece8ef45689a3ffaf70fb45d19862d7b93b2f92