Add deprecation notices

Change-Id: Ie69c1267d3ffd9f54f760c03f86e00d0e8192929

Author: yaraki

DownloadableFonts/README.md

@@ -1,3 +1,13 @@
+> **Warning**
+> This sample has been migraated to the new [platform-samples repository](https://github.com/android/platform-samples)
+> and will no longer be maintained. 
+> 
+> Please use the following
+>[sample](https://github.com/android/platform-samples/tree/main/samples/user-interface/text/src/main/java/com/example/platform/ui/text/DownloadableFonts.kt)
+> instead.
+>
+> Thank you for your understanding.
+
 Android DownloadableFonts Sample (Kotlin)
 ===================================
 

DragAndDrop/README.md

@@ -1,3 +1,13 @@
+> **Warning**
+> This sample has been migraated to the new [platform-samples repository](https://github.com/android/platform-samples)
+> and will no longer be maintained. 
+> 
+> Please use the following
+>[sample](https://github.com/android/platform-samples/tree/main/samples/user-interface/draganddrop)
+> instead.
+>
+> Thank you for your understanding.
+
 # Drag and Drop Demo
 
 ## This is not an official Google product
@@ -15,4 +25,4 @@ the process of implementing both dragging and dropping functionality.
 ## Screenshots
 ![Animation of the sample app. Text and images are dragged and dropped between two instances of the app](screenshots/drag-n-drop.gif)
 
-For reference and education only.
+For reference and education only.

Quick-Settings/README.md

@@ -1,3 +1,13 @@
+> **Warning**
+> This sample has been migraated to the new [platform-samples repository](https://github.com/android/platform-samples)
+> and will no longer be maintained. 
+> 
+> Please use the following
+>[sample](https://github.com/android/platform-samples/tree/main/samples/user-interface/quicksettings)
+> instead.
+>
+> Thank you for your understanding.
+
 ## Android N Quick Settings Codelab
 
 This folder contains an updated source code for a [Google I/O 2016 codelab on Android N Quick Settings](https://codelabs.developers.google.com/codelabs/android-n-quick-settings/#0). 

TextStyling/README.md

@@ -1,3 +1,13 @@
+> **Warning**
+> This sample has been migraated to the new [platform-samples repository](https://github.com/android/platform-samples)
+> and will no longer be maintained. 
+> 
+> Please use the following
+>[sample](https://github.com/android/platform-samples/tree/main/samples/user-interface/text/src/main/java/com/example/platform/ui/text/TextSpan.kt)
+> instead.
+>
+> Thank you for your understanding.
+
 Text Styling
 ============
 This sample shows how to style text on Android using spans, in Kotlin, using [Android KTX](https://github.com/android/android-ktx).

WindowInsetsAnimation/README.md

@@ -1,3 +1,13 @@
+> **Warning**
+> This sample has been migraated to the new [platform-samples repository](https://github.com/android/platform-samples)
+> and will no longer be maintained. 
+> 
+> Please use the following
+>[sample](https://github.com/android/platform-samples/blob/main/samples/user-interface/window-insets/src/main/java/com/example/platform/ui/insets/WindowInsetsAnimation.kt)
+> instead.
+>
+> Thank you for your understanding.
+
 WindowInsetsAnimation sample
 ============