Fixes NPEs when running call tests on auto targets without Telephony

Fixes some potential NPEs that can be generated by Telecom when there
is a call placed and Telephony is not available.

Fixes: 327806145
Test: atest CtsTelecomCujTestCases:SimultaneousCallingTest on auto CF target
Change-Id: I9910b6f224afbd4ebc5358173465a9f3f25a43d3