[Telephony] remove the RuntimeException thrown

Bug: 196880723
Test: ATP apct/device_boot_health_check_extra
      TMUS-Repeated test to unregistermmtel after registration.
          Volte dials/disconnects, airplane mode on/off,
          Sim removed, power on/off

Merged-In: I050d4affd403604bdae21ef3bc7f9ddf93ffa9e4
Change-Id: I16ebfe7edb13e950afd835d64691d740b11cbcdc