Revert "Re-enable pr-head"

This reverts commit 963493ae7f82b77ac340e6b9bec051565f74b83b.

Reason for revert: All jobs has been moved to the staging. the production jobs shouldn't be enabled.

Change-Id: I9229612c661428d3ee912d64d352c2e7bd2ccb8a
1 file changed