clang-format: [Java] Accept generic types in enum declaration

Before:
  enum Foo implements Bar<X, Y> {
    ABC {
      ...
    }
    , CDE {
      ...
    };
  }

After:
  enum Foo implements Bar<X, Y> {
    ABC {
      ...
    },
    CDE {
      ...
    };
  }

Patch by Harry Terkelsen.