Add more internal API's for assist

- When starting a voice interaction session from SysUI, a callback
can be passed to know when voice interaction has successfully started
- Add a new window type for the voice interaction starting window,
which resides behind the voice interaction layer.
- SystemUI now also inspects the voice interaction service to get the
logo asset for the starting window.
- Make VoiceInteractionSession window fullscreen, to accomodate for
the visuals.

Change-Id: If8c3c445e8b39841f48e8d153e6d1ba81e447286
diff --git a/core/java/android/view/WindowManager.java b/core/java/android/view/WindowManager.java
index 66dae7b..54d78f3 100644
--- a/core/java/android/view/WindowManager.java
+++ b/core/java/android/view/WindowManager.java
@@ -223,6 +223,7 @@
             @ViewDebug.IntToString(from = TYPE_MAGNIFICATION_OVERLAY, to = "TYPE_MAGNIFICATION_OVERLAY"),
             @ViewDebug.IntToString(from = TYPE_PRIVATE_PRESENTATION, to = "TYPE_PRIVATE_PRESENTATION"),
             @ViewDebug.IntToString(from = TYPE_VOICE_INTERACTION, to = "TYPE_VOICE_INTERACTION"),
+            @ViewDebug.IntToString(from = TYPE_VOICE_INTERACTION_STARTING, to = "TYPE_VOICE_INTERACTION_STARTING"),
         })
         public int type;
     
@@ -549,6 +550,12 @@
         public static final int TYPE_ACCESSIBILITY_OVERLAY = FIRST_SYSTEM_WINDOW+32;
 
         /**
+         * Window type: Starting window for voice interaction layer.
+         * @hide
+         */
+        public static final int TYPE_VOICE_INTERACTION_STARTING = FIRST_SYSTEM_WINDOW+33;
+
+        /**
          * End of types of system windows.
          */
         public static final int LAST_SYSTEM_WINDOW      = 2999;