Add getter for state of automatic adaptation

Closes #29

Author: Sanborn Hilland

lib/player/player.js

@@ -1008,6 +1008,15 @@ shaka.player.Player.prototype.enableAdaptation = function(enabled) {
 };
 
 
+/**
+ * @return {boolean} Return true if automatic bitrate adaptation enabled.
+ * @export
+ */
+shaka.player.Player.prototype.getAdaptationEnabled = function() {
+  return this.adaptationEnabled_;
+};
+
+
 /**
  * @return {number} Current playback time in seconds.
  * @export