Add WW log for drag events from longpress popup window.

Bug: 157765763
Sample Log: https://docs.google.com/document/d/1CBP2yTcXdFhPdNG5ZmWFKSgd8mDbMevY-akVlUXPLDo/edit#bookmark=id.368csp9y1pwc

Change-Id: I73024f2c8010e77b6f89829fda64130f54ff81f1
diff --git a/protos/launcher_atom.proto b/protos/launcher_atom.proto
index 5f5fab0..d552daf 100644
--- a/protos/launcher_atom.proto
+++ b/protos/launcher_atom.proto
@@ -51,6 +51,7 @@
     WidgetsContainer widgets_container = 5;
     PredictionContainer prediction_container = 6;
     SearchResultContainer search_result_container = 7;
+    ShortcutsContainer shortcuts_container = 8;
   }
 }
 
@@ -69,6 +70,11 @@
 message SearchResultContainer {
 }
 
+// Container for package specific shortcuts to deep links and notifications.
+// Typically shown as popup window by longpressing on an icon.
+message ShortcutsContainer {
+}
+
 enum Origin {
   UNKNOWN = 0;
   DEFAULT_LAYOUT = 1;       // icon automatically placed in workspace, folder, hotseat