Converter tests:

Change test data files extension to "java"

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

@@ -0,0 +1,10 @@
+//file
+class Library {
+  final static java.io.PrintStream ourOut;
+}
+
+class User {
+  void main() {
+    Library.ourOut.print();
+  }
+}