TIF: Specify the default implementation of onTune(Uri, Bundle)

Bug: 28146354
Change-Id: I3148ab4704a03c258d330c3b9a10513f950a8cfc
diff --git a/media/java/android/media/tv/TvInputService.java b/media/java/android/media/tv/TvInputService.java
index e134635..21211d7 100644
--- a/media/java/android/media/tv/TvInputService.java
+++ b/media/java/android/media/tv/TvInputService.java
@@ -839,9 +839,11 @@
         public abstract boolean onTune(Uri channelUri);
 
         /**
-         * Calls {@link #onTune(Uri)}. Override this method in order to handle domain-specific
+         * Tunes to a given channel. Override this method in order to handle domain-specific
          * features that are only known between certain TV inputs and their clients.
          *
+         * <p>The default implementation calls {@link #onTune(Uri)}.
+         *
          * @param channelUri The URI of the channel.
          * @param params Domain-specific data for this tune request. Keys <em>must</em> be a scoped
          *            name, i.e. prefixed with a package name you own, so that different developers
@@ -1693,11 +1695,12 @@
         public abstract void onTune(Uri channelUri);
 
         /**
-         * Calls {@link #onTune(Uri)}. Override this method in order to handle domain-specific
-         * features that are only known between certain TV inputs and their clients.
+         * Called when the application requests to tune to a given channel for TV program recording.
+         * Override this method in order to handle domain-specific features that are only known
+         * between certain TV inputs and their clients.
          *
          * <p>The application may call this method before starting or after stopping recording, but
-         * not during recording.
+         * not during recording. The default implementation calls {@link #onTune(Uri)}.
          *
          * <p>The session must call {@link #notifyTuned(Uri)} if the tune request was fulfilled, or
          * {@link #notifyError(int)} otherwise.