SystemUI: rewrite FPSInfoService in kt from scratch

* Basically the old one was total bs
* We now make use of coroutines for periodically reading fps
* Added support for controlling fps read interval via overlay
* Make sure tile is not available if fps info node is not accessible
* Also keep the overlay below statusbar inset

Change-Id: I789a9ea0941718473fef7e5344ce036b077120bd
Signed-off-by: jhonboy121 <alfredmathew05@gmail.com>
Signed-off-by: Dmitrii <bankersenator@gmail.com>
7 files changed