update_engine: Allow to access bootctrl_block_device.

update_engine needs to access bootctrl_block_device to get and set the slot to boot.
avc: denied { write } for name="mmcblk0boot1" dev="tmpfs" ino=1266 scontext=u:r:update_engine:s0 tcontext=u:object_r:bootctrl_block_device:s0 tclass=blk_file
avc: denied { open } for path="/dev/block/mmcblk0boot1" dev="tmpfs" ino=1266 scontext=u:r:update_engine:s0 tcontext=u:object_r:bootctrl_block_device:s0 tclass=blk_file

Also track the name change of the native binder service.
avc:  denied  { add } for service=android.os.UpdateEngineService pid=210 uid=0 scontext=u:r:update_engine:s0 tcontext=u:object_r:default_android_service:s0 tclass=service_manager

Bug: 27106053
Change-Id: Idbfef18578489db33fead0721e8f26d63db5ce09