The data is encrypted at rest with a key that is
managed by the customer. The active version of the key. kms_key_version
will be populated, and encryption_status may be populated.
GoogleDefaultEncryption
The data is encrypted at rest with a key that is
fully managed by Google. No key version or status will be populated.
This is the default state.
Unspecified
Encryption type was not specified, though data at rest remains encrypted.