Fix enrollment cancelation race conditions. Bug: 210090299 Change-Id: Idd1485f182cf841b96ced1dab4b8330ff3b57c2a Merged-In: Idd1485f182cf841b96ced1dab4b8330ff3b57c2a (cherry picked from commit abc127673bf8f030cfb92d2f94d8f14baf9cd2aa) Merged-In:Idd1485f182cf841b96ced1dab4b8330ff3b57c2a