* INCLUDE_AWX_VAR_PREFIX to USE_TOWER_VAR_PREFIX boolean toggle replace the include legacy prefix boolean with a tower-or-awx toggle USE_TOWER_VAR_PREFIX=True (default) emits only tower_ prefixed variables, false emits only awx_ (deprecated)
* Clean up dead constant and cache get_job_variable_prefixes() calls
* Revise tests to reflect new behavior
* Fix fragile fallback test to actually exercise getattr default
* Fix mock target for settings fallback test