This fixes an issue where leaf certificates issued in secondary
datacenters would be reissued very frequently (every ~20 seconds)
because the logic meant to detect root rotation was errantly triggering
because a hash of the ultimate root (in the primary) was being compared
against a hash of the local intermediate root (in the secondary) and
always failing.
The fields in the certs are meant to hold the original binary
representation of this data, not some ascii-encoded version.
The only time we should be colon-hex-encoding fields is for display
purposes or marshaling through non-TLS mediums (like RPC).