Fix build breakage due to missing methods on TestCallService.

Change-Id: Idc862eeef713d553c37e6d0b7c3bd69c1a8aa7f9
diff --git a/tests/src/com/android/telecomm/testcallservice/TestCallService.java b/tests/src/com/android/telecomm/testcallservice/TestCallService.java
index f3fb95a..4e459a3 100644
--- a/tests/src/com/android/telecomm/testcallservice/TestCallService.java
+++ b/tests/src/com/android/telecomm/testcallservice/TestCallService.java
@@ -167,6 +167,20 @@
 
     /** {@inheritDoc} */
     @Override
+    public void playDtmfTone(String callId, char digit) {
+        Log.i(TAG, "playDtmfTone(" + callId + "," + digit + ")");
+        // TODO(ihab): Implement
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public void stopDtmfTone(String callId) {
+        Log.i(TAG, "stopDtmfTone(" + callId + ")");
+        // TODO(ihab): Implement
+    }
+
+    /** {@inheritDoc} */
+    @Override
     public void onAudioStateChanged(String callId, CallAudioState audioState) {
     }