SystemUI: add FloatingRotationButton for hw-key devices

This is a squash of the following commits:

Author: Michal Pražák <Michal.prazak1@gmail.com>
Date:   Thu Jan 9 11:37:29 2020 +0100

    SystemUI: add FloatingRotationButton for hw-key devices

    Add floating rotation button for hardware key devices.
    Screenshot: https://imgur.com/a/KPNGD43



    Co-authored-by: Timi <timi.rautamaki@gmail.com>
    Change-Id: I181d0b94cf1b740c20313ee556308f237cc3fd3f

Author: Timi Rautamäki <timi.rautamaki@gmail.com>
Date:   Thu Jan 6 12:01:10 2022 +0000

    SystemUI: don't show FRB when IME is visible

    Change-Id: I97a99cc1b98ac9ee1e623fe8f2782434c76f9ce0

Change-Id: I26953cb83edc28483b88cad61affade526647cbe