[Media, UI] Change MediaNotification style to MediaStyle

chrome/android/java/proguard.flags

 # Keep line number information, useful for stack traces.
 -keepattributes SourceFile,LineNumberTable
 
 # Keep the annotations.
 -keep @interface ***
 
 # Disable obfuscation for the following two packages.
 -keepnames class com.google.android.apps.chrome.**,org.chromium.** {
   *;
 }
@@ skipping 94 matching lines @@
 }
 
 -keep class android.support.v4.app.FragmentManager** {
   *;
 }
 
 -keep class android.support.v4.app.DialogFragment** {
   *;
 }
 
--keep class android.support.v4.app.NotificationCompat** {
+-keep class android.support.v7.app.NotificationCompat** {
   *;
 }
 
 -keep class android.support.v7.app.AlertDialog** {
   *;
 }
 
 -keep class com.google.android.gms.cast.CastMediaControlIntent* {
   *;
 }
@@ skipping 41 matching lines @@
 #-keep public class android.webkit.WebVie
 
 #-dontwarn android.webkit.WebView
 -dontwarn android.net.http.SslCertificate
 
 # Needed for assertions in BaseChromiumApplication.
 # TODO(twellington): Remove these two lines when support for detecting a debug
 # build lands (https://codereview.chromium.org/1597273005/).
 -keep class android.support.v7.app.ToolbarActionBar$ToolbarCallbackWrapper {*;}
 -keep class android.support.v7.internal.app.ToolbarActionBar$ToolbarCallbackWrapper {*;}