flatc java generator: namespace_test2.fbs is missing namespace prefix for referToA2() return type (#4040)

* Fix flatc generating incorrect java/c# code for namespace_test2.fbs. In code for TableInC, method referToA2() returned type SecondTableInA instead of NamespaceA.SecondTableInA.

* Updated generated code.

* Fixed indendation.
5 files changed