LineageOS: update to lineage-21.0
Backgrounds: untrack
16.0 is long eol'ed, and we cannot support PARTNER_CUSTOMIZATION variant
after that which requires being system app
Aperture: update build-tools
Jelly: bump build-tools for newer agp
build: remove [multilib] hack
[multilib] is now enabled in the base image
Aperture: update built-tools for newer agp
Recorder: update build-tools for newer agp
build: handle multiple apks
update: support not specifying build-tools version
unversioned aur package seems not to provide versioned virtual now.
build: support kotlin gradle config
LineageOS/android_packages_apps_Recorder: build-tools 30.0.3