Revert "Simplify some tests in AssistedDialingMediatorImplTest"

This reverts commit c8fd511bf992e68718ebe72f8efd91f90b3e5150.

Reason for revert: we're cutting the feature from P

Change-Id: Ic756d657e17b2f03f0232f05925a400787e62c81
Bug: 73727182
1 file changed