Add metrics event for Settings->Display->Ambient Display.

am: f3cd2c6116

Change-Id: If0d2928854e1aba8957e6956bbdcea99f37df79a

proto/src/metrics_constants.proto

@@ -2203,6 +2203,10 @@ message MetricsEvent {
     // System navigation key down.
     ACTION_SYSTEM_NAVIGATION_KEY_DOWN = 494;
 
+    // OPEN: Settings > Display -> Ambient Display
+    // CATEGORY: SETTINGS
+    ACTION_AMBIENT_DISPLAY = 495;
+
     // ---- End N-MR1 Constants, all N-MR1 constants go above this line ----
     // Add new aosp constants above this line.
     // END OF AOSP CONSTANTS