Adjust layers for system overlays.

Prevent system overlays from showing above the notification bar.

Allow secure system overlays to be fullscreen, for the pointer
location view.

Show the drag layer above the notification bar.

Change-Id: Ic8d663792a243cca2cd9952d241d001e0357d551
diff --git a/services/input/InputWindow.h b/services/input/InputWindow.h
index 8861bee..38968f9 100644
--- a/services/input/InputWindow.h
+++ b/services/input/InputWindow.h
@@ -103,6 +103,8 @@
         TYPE_STATUS_BAR_SUB_PANEL  = FIRST_SYSTEM_WINDOW+17,
         TYPE_POINTER            = FIRST_SYSTEM_WINDOW+18,
         TYPE_NAVIGATION_BAR     = FIRST_SYSTEM_WINDOW+19,
+        TYPE_VOLUME_OVERLAY = FIRST_SYSTEM_WINDOW+20,
+        TYPE_BOOT_PROGRESS = FIRST_SYSTEM_WINDOW+21,
         LAST_SYSTEM_WINDOW      = 2999,
     };