Add permissions for hal_boot

The service running the boot control HAL needs the permissions
provided by the boot_control_hal attribute. update_engine and
update_verifier still also need these permissions in order
to successfully call the new HAL in pass-through mode, but also
need permission to call the new service.

Bug: 31864052
Test: Built and confirmed no permission denials.
Change-Id: I2a6fdd5cf79b9e461d7cc14bd5b7abd6481ed911
Signed-off-by: Connor O'Brien <connoro@google.com>