Notify voicemail only for voice-capable device.

Only allow voicemail waiting notification for
device supporting voice-capable service.

Bug: 3038102
Change-Id: I7ee1f973755f007cdcd87c4326bc55229a575598

telephony/java/com/android/internal/telephony/PhoneBase.java

@@ -742,6 +742,10 @@ public abstract class PhoneBase extends Handler implements Phone {
     }
 
     public void notifyMessageWaitingIndicator() {
+        // Do not notify voice mail waiting if device doesn't support voice
+        if (!mIsVoiceCapable)
+            return;
+
         // This function is added to send the notification to DefaultPhoneNotifier.
         mNotifier.notifyMessageWaitingChanged(this);
     }