Merge changes from topics "runtime-apex-otapreopt_chroot-tear-down", "runtime-apex-installd-support", "runtime-apex-otapreopt_chroot-support"

* changes:
  Allow `oatpreopt_chroot` to deactivate APEX packages in `/postinstall/apex`.
  Allow `oatpreopt` to run `dex2oat` from the Runtime APEX.
  Allow `otapreopt_chroot` to mount APEX packages using `apexd` logic.