ImsConferenceControllerTest extends TelephonyTestBase

This will improve test isolation and reduce test code duplication.

Also, pretend to support Telephony calling

Bug: 365800992
Test: atest com.android.services.telephony.ImsConferenceControllerTest
Flag: EXEMPT only test + extra assertions
Change-Id: Ie350aa91555a4b74c72c2b2ada2862a28370e553
diff --git a/tests/src/com/android/TestContext.java b/tests/src/com/android/TestContext.java
index e464ad5..6e14574 100644
--- a/tests/src/com/android/TestContext.java
+++ b/tests/src/com/android/TestContext.java
@@ -212,6 +212,11 @@
     }
 
     @Override
+    public Looper getMainLooper() {
+        return Looper.getMainLooper();
+    }
+
+    @Override
     public Handler getMainThreadHandler() {
         return new Handler(Looper.getMainLooper());
     }