Catch double unbind of dead service

If a service receives onBindingDied after it has successfully connected
once, unbindService would be called once from the onBindingDied and then
again from registerServiceLocked when the service was rebound.  This
second attempt would typically crash.

The first unbindService call has a try/catch, add one around the second
call as well.

Test: Manual.  Boots and reboots without problems.
Change-Id: Ie9eabbcb6ee89c05abc565427465cfd6906f3fa3