Further cleanup, and move functionality into TestFixture objects

Change-Id: I62b514ae8fe10f720a60c681968efd2340616eba
diff --git a/src/com/android/server/telecom/CallsManager.java b/src/com/android/server/telecom/CallsManager.java
index bd60116..c6b2982 100644
--- a/src/com/android/server/telecom/CallsManager.java
+++ b/src/com/android/server/telecom/CallsManager.java
@@ -56,7 +56,8 @@
  * access from other packages specifically refraining from passing the CallsManager instance
  * beyond the com.android.server.telecom package boundary.
  */
-public final class CallsManager extends Call.ListenerBase {
+@VisibleForTesting
+public class CallsManager extends Call.ListenerBase {
 
     // TODO: Consider renaming this CallsManagerPlugin.
     interface CallsManagerListener {