Run alter hook for all code paths in `environment_indicator_get_active`.
requested to merge issue/environment_indicator-3465337:3465337-cached-environment-indicator into 7.x-2.x
hook_environment_indicator_matched_indicator_alter was never invoked on the cached environment object. Also eliminates an unneeded cache_set when environment is overridden in settings.php.
Also cache the queried git release, as the git command would otherwise be called on every page request.
Closes #3465337