Update sample templates for android-23 release

Converted "android-MNC" build target references (including
min/compile) to use "23" instead, to correspond with
recent SDK builds.

Includes source file refresh.

Change-Id: I441aba7b50d16179cc231531e6aeffd108cdd404
diff --git a/ui/window/AdvancedImmersiveMode/README.md b/ui/window/AdvancedImmersiveMode/README.md
index f3a5546..a0b2fdd 100644
--- a/ui/window/AdvancedImmersiveMode/README.md
+++ b/ui/window/AdvancedImmersiveMode/README.md
@@ -1,19 +1,40 @@
+
 Android AdvancedImmersiveMode Sample
-==============================
+===================================
 
-
-\n"Immersive Mode", added in Android 4.4, improves the "hide full screen" and
-"hide nav bar" modes, by letting users swipe the bars in and out.This sample
+Immersive Mode, added in Android 4.4, improves the "hide full screen" and
+"hide nav bar" modes by letting users swipe the bars in and out.  This sample
 lets the user experiment with immersive mode by seeing how it interacts
 with some of the other UI flags related to full-screen apps.
 
+Introduction
+------------
+
+Android 4.4 (API Level 19) introduces a new `SYSTEM_UI_FLAG_IMMERSIVE`
+flag for [setSystemUiVisibility()][1] that lets your app go truly "full
+screen." This flag, when combined with the `SYSTEM_UI_FLAG_HIDE_NAVIGATION` and
+`SYSTEM_UI_FLAG_FULLSCREEN` flags, hides the navigation and status bars
+and lets your app capture all touch events on the screen.
+
+When immersive full-screen mode is enabled, your activity continues
+to receive all touch events. The user can reveal the system bars with
+an inward swipe along the region where the system bars normally
+appear.
+
+[1]: http://developer.android.com/reference/android/view/View.html#setSystemUiVisibility(int)
+
 Pre-requisites
 --------------
 
-- Android SDK v20
-- Android Build Tools v20
+- Android SDK v23
+- Android Build Tools v22.0.1
 - Android Support Repository
 
+Screenshots
+-------------
+
+<img src="screenshots/immersion.png" height="400" alt="Screenshot"/> <img src="screenshots/leanback.png" height="400" alt="Screenshot"/> 
+
 Getting Started
 ---------------
 
@@ -44,7 +65,7 @@
 use this file except in compliance with the License.  You may obtain a copy of
 the License at
 
-  http://www.apache.org/licenses/LICENSE-2.0
+http://www.apache.org/licenses/LICENSE-2.0
 
 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS, WITHOUT