Recorder: update UI

* Deprecate 2-tabs layout, use a simple single-screen interface
* Make screen-recorder overlay interface rounded
* Show screen recorder settings and last item in a dialog
* OnBoarding

Ticket: LINN-31

Read more: https://medium.com/@jrizzoli/recording-awesomeness-bc1c5ffe2826



Change-Id: I910af7454eedfd52ec0f1904a52990d2d6f890e7
Signed-off-by: Joey Rizzoli <joey@lineageos.org>