Change Project to only expose the configured submit type for that
project, and modify all callers to call the equivalent method on
ProjectState which respects inheritance.
In the extension/REST API, expose the inherited submit type analogously
to the inherited boolean values, using an object containing configured
and inherited values. For backwards compatibility, leave the old
submit_type field as-is, but mark it deprecated, in the hopes that we
can eventually replace it.
Do not change the default of a project with no configured submit type,
leaving the default as MERGE_IF_NECESSARY. This avoids, for now, the
need for migrating existing projects that do not have a submit type set,
including those that were created outside of Gerrit and don't have
refs/meta/config at all.
After this change, the global `repository.<name>.defaultSubmitType`
configuration still takes effect when creating a new project. A later
change may remove support for defaultSubmitType, but the migration to
convert global config into appropriate inheritable config values is
nontrivial, so we're punting on it.
Change-Id: Ib5711baaa67b2c92239a1ff4564349a80d211c28
c8f8d2ea83