Revert "Introduce a new headless-user-mode attribute"

Revert submission 27247835-headlessDoAttribute

Reason for revert: potential root cause for b/339271272

Reverted changes: /q/submissionid:27247835-headlessDoAttribute

Change-Id: Ic1212e6d1c6d01bf49000193081e748e948ce797
4 files changed