ConstReadonlyPRINCIPAL_TYPE_UNSPECIFIED: "PRINCIPAL_TYPE_UNSPECIFIED"Default; an unset principal type is rejected.
ReadonlySERVICE_PRINCIPAL: "SERVICE_PRINCIPAL"A Databricks service principal, identified by its application (client) id.
ReadonlyUSER: "USER"A Databricks user, identified by email.
The kind of Databricks principal a store permission is granted to.