Make TvContentRating.contains() public

Apply the feedback from API council.

Bug: 25726616
Change-Id: I9858a61eea50ff95221d453117fe3d991f88a33f
diff --git a/api/current.txt b/api/current.txt
index 96ecad6..5aab986 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -17776,6 +17776,7 @@
 package android.media.tv {
 
   public final class TvContentRating {
+    method public final boolean contains(android.media.tv.TvContentRating);
     method public static android.media.tv.TvContentRating createRating(java.lang.String, java.lang.String, java.lang.String, java.lang.String...);
     method public java.lang.String flattenToString();
     method public java.lang.String getDomain();
diff --git a/media/java/android/media/tv/TvContentRating.java b/media/java/android/media/tv/TvContentRating.java
index 043b80e..6197c70 100644
--- a/media/java/android/media/tv/TvContentRating.java
+++ b/media/java/android/media/tv/TvContentRating.java
@@ -931,9 +931,7 @@
      *
      * @param rating The {@link TvContentRating} to check.
      * @return {@code true} if this object contains {@code rating}, {@code false} otherwise.
-     * @hide
      */
-    @SystemApi
     public final boolean contains(@NonNull TvContentRating rating) {
         Preconditions.checkNotNull(rating);
         if (!rating.getMainRating().equals(mRating)) {