Fixing up the encoding of the BCC

According to the CDDL specification, the public key at the beginning of
the BCC chain should not be serialized out to a bstr, but remain as a
map. This makes sense, since the field itself is not directly being used
in any cryptographic operations as AAD or ciphertext.

Test: The RPK server stops returning error 500 on bad parsing :)
Change-Id: I59b73503ca3a25e398b016bba25fa2c28b792e86
1 file changed