[enhancement] Play/pause buttons should also show the overlay menu

• Version: 2.1.9 (nightly)
• Device: Beelink gt1 (Android 6.0 box with remote control)

While playing a video, the "down" arrow button is the only way to display the overlay menu from the remote control (which seems to be confirmed by this code). The remote control of the Beelink gt1 does not provide a "A" button.

Moreover, when pressing the ok/play/pause button, the video pauses, but no message is displayed (nor any menu).

I think it should be a bit more intuitive if play/pause key events was toggling the overlay menu (with a timeout, like the touch events) and focus on the play/pause button, in addition to the resume/pause effect.

It would solve the absence of play/pause message, as well as having an easy and quick access to the overlay menu.