Removed C# references from java generator. Move annotations closer to definitions (#6204)

tests/MyGame/Example/Monster.java

@@ -7,10 +7,10 @@ import java.lang.*;
 import java.util.*;
 import com.google.flatbuffers.*;
 
-@SuppressWarnings("unused")
 /**
  * an example documentation comment: "monster object"
  */
+@SuppressWarnings("unused")
 public final class Monster extends Table {
   public static void ValidateVersion() { Constants.FLATBUFFERS_1_12_0(); }
   public static Monster getRootAsMonster(ByteBuffer _bb) { return getRootAsMonster(_bb, new Monster()); }