Review: Update according to review

library/ui/proguard-rules.txt

@@ -4,6 +4,7 @@
 -dontnote androidx.appcompat.app.AlertDialog.Builder
 -keepclassmembers class androidx.appcompat.app.AlertDialog$Builder {
   <init>(android.content.Context);
+  <init>(android.content.Context, int);
   public android.content.Context getContext();
   public androidx.appcompat.app.AlertDialog$Builder setTitle(java.lang.CharSequence);
   public androidx.appcompat.app.AlertDialog$Builder setView(android.view.View);

library/ui/src/main/java/com/google/android/exoplayer2/ui/TrackSelectionDialogBuilder.java

@@ -123,7 +123,12 @@ public final class TrackSelectionDialogBuilder {
                     newOverrides.isEmpty() ? null : newOverrides.get(0)));
   }
 
-  public TrackSelectionDialogBuilder setTheme(int themeResId) {
+  /**
+   * Sets the resource ID of the theme used to inflate this dialog.
+   * @param themeResId the resource ID to use
+   * @return This builder, for convenience.
+   */
+  public TrackSelectionDialogBuilder setTheme(@StyleRes  int themeResId) {
     this.themeResId = themeResId;
     return this;
   }