Pipe TelephonyManager.getCallState through TelecommManager

* Add TelecommManager.getCallState (hidden API)
* Make TelephonyManager.getCallState call through to
TelecommManager, to be consistent with
TelephonyManager.ACTION_PHONE_STATE_CHANGED broadcasts for
overall call state. Telephony continues to manage call states for
individual subscriptions.

Bug: 17378767
Change-Id: Ia5e8b21df801ed3af4f6e14c110a72c92f077f88
diff --git a/telecomm/java/com/android/internal/telecom/ITelecomService.aidl b/telecomm/java/com/android/internal/telecom/ITelecomService.aidl
index 4edce53..4875cc3 100644
--- a/telecomm/java/com/android/internal/telecom/ITelecomService.aidl
+++ b/telecomm/java/com/android/internal/telecom/ITelecomService.aidl
@@ -139,6 +139,11 @@
     boolean isRinging();
 
     /**
+     * @see TelecomServiceImpl#getCallState
+     */
+    int getCallState();
+
+    /**
      * @see TelecomServiceImpl#endCall
      */
     boolean endCall();