Add back in hack to call getVRDisplays on enter

src/scene-entry-manager.js

@@ -51,6 +51,9 @@ export default class SceneEntryManager {
     }
 
     if (enterInVR) {
+      // HACK - A-Frame calls getVRDisplays at module load, we want to do it here to
+      // force gamepads to become live.
+      navigator.getVRDisplays();
       this.scene.enterVR();
     } else if (AFRAME.utils.device.isMobile()) {
       document.body.addEventListener("touchend", requestFullscreen);