Bring back font and icon shape customization

Author: Michael Bestas <mkbestas@gmail.com>
Date:   Thu Jan 20 00:03:45 2022 +0200

    Bring back font and icon shape customization

    * AOSP removed those settings from ThemePicker,
      we can add them back here since the underlying mechanism
      still exists and works perfectly.

    Change-Id: I84449f0b3c95654b0caa5c7654a86f397da0ced4

Author: Michael Bestas <mkbestas@lineageos.org>
Date:   Mon Mar 14 17:02:16 2022 +0200

    OverlayCategoryPreferenceController: Change the way we set overlays

    Before this patch, we were just setting overlays on the fly
    without saving them anywhere persistent, which ended up
    removing font and icon shape customizations on wallpaper change
    or device reboot.

    Modify Settings.Secure.THEME_CUSTOMIZATION_OVERLAY_PACKAGES
    instead and SystemUI will apply the overlays automatically.

    Test: Change wallpaper, observe font and icon shape customizations
          are still applied.
    Change-Id: Idc50dc1cea1cdb239a0949425f14277c6d1ce332

Change-Id: Ib2727d28b4f570c5664d731f9bcd37433084f659