shutdownMobileRadios API shuts down multiple Radios on MSIM devices and also gracefully shuts down Radios and SIM cards on single SIM and MSIM devices. Use this API instead of the old setRadio APIs. Add RIL_REQUEST_SHUTDOWN to RILConstants. Message is sent to notify RIL that the device is shutting down. Bug: 9773278 Change-Id: I6afa9e810cefc7855f7ae42e51f39cc51fa2aa6e