IImsCallSession AIDL calls are handled on a different thread for MT calls

Set executor for ImsCallSessionImplBase as it of MmTelFeatured for incoming call

Bug: 257552525
Test: E2E call regression test has completed
      refer to : https://b.corp.google.com/issues/257552525#comment11

Change-Id: I9af70dd7afc476e2b346889fe758ea404da10c92

telephony/java/android/telephony/ims/feature/MmTelFeature.java

@@ -700,6 +700,7 @@ public class MmTelFeature extends ImsFeature {
             throw new IllegalStateException("Session is not available.");
         }
         try {
+            c.setDefaultExecutor(MmTelFeature.this.mExecutor);
             listener.onIncomingCall(c.getServiceImpl(), extras);
         } catch (RemoteException e) {
             throw new RuntimeException(e);