- init will set sys.powerctl property and run bootanim.
- Use /oem/media/shutdownanimation.zip or
/system/media/shutdownanimation.zip for animation file.
If none of them exist, android animation will be used.
- Disable audio playing for shutdown animation.
- Disable TimeCheckThread for shutdown animation. It
accesses /data partition and can block umount.
bug: 36526187
Test: many reboots
Change-Id: If02c73cda2015317d88d056cd45201208da49946
