Revert "Clean up unused code of PRIORITY"

Revert submission 2737117-bt-clean-up-priority

Reason for revert: DroidMonitor-triggered revert due to breakage https://android-build.corp.google.com/builds/quarterdeck?branch=git_udc-mainline-prod&target=test_suites_arm&lkgb=10777828&lkbb=10779852&fkbb=10779852, bug b/299586546

BUG: b/299586546

Reverted changes: /q/submissionid:2737117-bt-clean-up-priority

Change-Id: Ib6e500bec83580198568755c676eb29c11cb5f8e