Don't use the `su` domain for art_boot.

It only works on userdebug, and we need to introduce a domain for it in
sepolicy instead. This amends
commit 4cdcab58b438a91c91cd5b09235c703251c6e328.

Test: boot
      -> Check that dalvik.vm.useartservice is not false
      adb root
      adb shell setprop persist.device_config.runtime_native_boot.useartservice false
      -> Check that dalvik.vm.useartservice is not false
      adb reboot
      -> Check that dalvik.vm.useartservice is false
  on udc-dev
Bug: 281850017
Ignore-AOSP-First: Will cherry-pick to AOSP later
Change-Id: Icb0ff95e341a23cf452cfb803fb43f5f46ef316e