When system server goes down, crash admins.

Apps making calls into the system server may end up persisting
internal state or making security decisions based on the perceived
success or failure of a call, or the default values returned.

The reality is that if the system process just died, init will be
along shortly to kill all running apps, so we should have no problem
rethrowing the RemoteException as a RuntimeException.

Bug: 27364859
Change-Id: I866a8c3c9682da1de2a31fe8b4ffcc9d7f4d8ba0