Converter tests:

Change test data files extension to "java"

j2k/tests/testData/ast/callChainExpression/libraryStringFieldCall.java

@@ -0,0 +1,10 @@
+//file
+class Library {
+  final public String myString;
+}
+
+class User {
+  void main() {
+    Library.myString.isEmpty();
+  }
+}