Add atom and logging for app overlay

Test: will add cts test
Change-Id: I8573abd8ec920467047fd0db9d9ce22173d84960
diff --git a/cmds/statsd/src/atoms.proto b/cmds/statsd/src/atoms.proto
index e64b631..ed570e7 100644
--- a/cmds/statsd/src/atoms.proto
+++ b/cmds/statsd/src/atoms.proto
@@ -96,6 +96,7 @@
         ShutdownSequenceReported shutdown_sequence_reported = 56;
         BootSequenceReported boot_sequence_reported = 57;
         DaveyOccurred davey_occurred = 58;
+        OverlayStateChanged overlay_state_changed = 59;
         // TODO: Reorder the numbering so that the most frequent occur events occur in the first 15.
     }
 
@@ -979,6 +980,25 @@
 }
 
 /**
+ * Logs overlay action
+ * Logged from:
+ *     services/core/java/com/android/server/wm/Session.java
+ */
+message OverlayStateChanged {
+    optional int32 uid = 1;
+
+    optional string package_name = 2;
+
+    optional bool using_alert_window = 3;
+
+    enum State {
+        ENTERED = 1;
+        EXITED = 2;
+    }
+    optional State state = 4;
+}
+
+/**
  * Pulls bytes transferred via wifi (Sum of foreground and background usage).
  *
  * Pulled from: