Currently, NoteDbSchemaVersionManager class cannot access
NoteDbSchemaVersions.LATEST constant, and instead a hard coded value is
used. This approach is very error prone as recent schema migration 181
has shown. As mentioned in TODO comment, this class can now be easily
moved to c.g.g.server.schema package, and hard coded value can be
replaced with NoteDbSchemaVersions.LATEST constant.
Change-Id: I301c4f2c93bb0cf384574d358e110f770102ed4f
3ae4ff2e4d