Correct default bit_length to match schema constraint
Correct default bit_length to match schema constraint

Closes-Bug: #1338725
Change-Id: I37a903d1d6bbf32b299378f97c1a99cce24c5758

MCDong/barbican,cneill/barbican,cneill/barbican,openstack/barbican,jmvrbanac/barbican,MCDong/barbican,cloudkeep/barbican,cloudkeep/barbican,jmvrbanac/barbican,openstack/barbican