Default How to change default app for bluetooth media controls

Does anyone know if it's possible to select which app functions as the default for Bluetooth media controls? I use Google Play Music as my primary music player, but my bluetooth media controls always invoke the stock media player. Before the 4.3 update, the Play Music app would respond to my media controls. After updating and hard resetting, the stock music player hijacked my media controls. I know it's possible for another app to take over the controls because I installed PowerAMP temporarily and it took over my media controls.

Is there any way I can get the Google Play Music app to take over the media controls? Is there any way to disable the stock music player?