Help out issue #6654729: CAB + screen off during playback

People generally expect, if they are using FLAG_KEEP_SCREEN_ON,
that the screen won't immediately dim after it is cleared, even
if it has been passed the user activity timeout since the last
user interaction.  So include the flag to reset the user activity
timeout when releasing its wake lock.

Change-Id: If7a8fea8faef3edbf13dff10a2f248adc9e3ff0b