DO NOT MERGE - NuPlayer: invalid anchor time when render is flushed.

Also rememeber the pause time in NuPlayerDriver.

Bug: 18436336
Change-Id: If09f680a0d0f9137bd55c5f94201eb3aa783278a
DO NOT MERGE - NuPlayer: open audio sink in offload mode when resuming from timeout teardown.

Also always recheck if a new stream can do offload.

Bug: 18154425
Change-Id: I121877834bd963eeeba91a2b951fd30d5dc36a8b