Set Binder to null if linkToDeath throws RemoteException

If linkToDeath throws a RemoteException, set the Binder to null in
order to stop unlinkToDeath from causing the phone process to crash.

For further safety, catch NoSuchElementException directly if it
still happens, as it should just result in a no-op.

Bug: 175737956
Test: manual; atest ImsCommonTests
Change-Id: I743d1768720cee6ef264ef3168183563652e50c4