Case finished without waiting for hal result

In VTS case RadioNeteworkTest#setEmergencyMode,
Case finishes without waiting for the result of exitEmergencyMode.
When the response is back, destroyed mutex will be used,
It will lead case end abnormally.

So, waiting for the response of exitEmergencyMode is necessary.

Bug: 352533464
Test: run VTS case RadioNetworkTest#setEmergencyMode

Change-Id: I52c527195b71e112275d74c80d0f9c91e42b3041