Revert "[automerge] [DO NOT MERGE]Revert "Relax minimum signatur..."

Revert "[DO NOT MERGE]Revert "Relax minimum signature scheme ver..."

Revert submission 16943318-presubmit-am-bc566b73c1674298b82a1153c03313a1

Reason for revert: This change breaks Better Bug.
Reverted Changes:
I32a2db8c7:[automerge] [DO NOT MERGE]Revert "Relax minimum si...
Ic53d2a361:[DO NOT MERGE]Revert "Relax minimum signature sche...

Change-Id: I847740b01073d4a7adde1e7b80243cd98cf2e722