NuPlayerRenderer: extend offload pause wakelock duration

Hold the NuPlayerRenderer offload pause timeout wakelock for a little
more after the audio path is torn down to leave time for the entire
stop sequence to complete before the wakelock is released.

Bug: 234429395
Test: repro steps in bug
Change-Id: I1523f60711b4fb5869b4bf987e3bc9c771c38159