Converter tests:

Change test data files extension to "java"

j2k/tests/testData/ast/issues/kt-809-string.java

@@ -0,0 +1,22 @@
+//file
+package demo;
+
+class Container {
+  String myString = "1";
+}
+
+class One {
+  static Container myContainer = new Container();
+}
+
+class StringContainer {
+  StringContainer(String s) {}
+}
+
+class Test {
+  void putString(String s) { }
+  void test() {
+    putString(One.myContainer.myString);
+    new StringContainer(One.myContainer.myString);
+  }
+}