When long pressing recents and already docked, undock

Bug: 26771328
Change-Id: I1fe12181cd80fd948e4184be6a8790c77bfe9e45
diff --git a/proto/src/metrics_constants.proto b/proto/src/metrics_constants.proto
index 0e67a24..85951ef 100644
--- a/proto/src/metrics_constants.proto
+++ b/proto/src/metrics_constants.proto
@@ -342,11 +342,15 @@
 
     // QS Tile for Data Saver.
     QS_DATA_SAVER = 284;
-
+    
     // OPEN: Settings > Security > User credentials
     // CATEGORY: Settings
     // OS: 6.1
     // GMS: 7.8.99
     USER_CREDENTIALS = 285;
+
+    // Logged when the user undocks a previously docked window by long pressing recents while in
+    // docked mode.
+    ACTION_WINDOW_UNDOCK_LONGPRESS = 285;
   }
 }