testsuite: Allow user to override minimal logging

The testsuite was always forcing minimal logging. This is problematic
as it does not allow user to see full logging string. Allow user to
override the minimal logging if needed, the default is still to
enable minimal logging.

[DL: Commit 7f08061f reverts this.
     Since this is useful, let's re-apply this.]

Fixes #34696

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Daniel Leung <daniel.leung@intel.com>