Move DecoratedCustomViewStyle to Compat Library

Deprecate the DecoratedCustomViewStyle in v7
NotificationCompat, folding the implementation into
Compat's v4 NotificationCompat.

Test: Manual inspection
BUG: 28983951
Change-Id: Idc1f9f520bbc6564033d063b9534a7c53927c9ef
diff --git a/api/26.0.0-SNAPSHOT.txt b/api/26.0.0-SNAPSHOT.txt
index e022198..46840e4 100644
--- a/api/26.0.0-SNAPSHOT.txt
+++ b/api/26.0.0-SNAPSHOT.txt
@@ -6537,6 +6537,10 @@
     method public android.support.v4.app.NotificationCompat.CarExtender.UnreadConversation.Builder setReplyAction(android.app.PendingIntent, android.support.v4.app.RemoteInput);
   }
 
+  public static class NotificationCompat.DecoratedCustomViewStyle extends android.support.v4.app.NotificationCompat.Style {
+    ctor public NotificationCompat.DecoratedCustomViewStyle();
+  }
+
   public static abstract interface NotificationCompat.Extender {
     method public abstract android.support.v4.app.NotificationCompat.Builder extend(android.support.v4.app.NotificationCompat.Builder);
   }
@@ -10489,8 +10493,8 @@
     ctor public deprecated NotificationCompat.Builder(android.content.Context);
   }
 
-  public static class NotificationCompat.DecoratedCustomViewStyle extends android.support.v4.app.NotificationCompat.Style {
-    ctor public NotificationCompat.DecoratedCustomViewStyle();
+  public static deprecated class NotificationCompat.DecoratedCustomViewStyle extends android.support.v4.app.NotificationCompat.DecoratedCustomViewStyle {
+    ctor public deprecated NotificationCompat.DecoratedCustomViewStyle();
   }
 
   public static class NotificationCompat.DecoratedMediaCustomViewStyle extends android.support.v7.app.NotificationCompat.MediaStyle {