Converter tests:

Change test data files extension to "java"

j2k/tests/testData/ast/rawGenerics/kt-540-rawGenericClass.java

@@ -0,0 +1,16 @@
+//file
+package demo;
+
+class Collection<E> {
+  Collection(E e) {
+    System.out.println(e);
+  }
+}
+
+class Test {
+  void main() {
+    Collection raw1 = new Collection(1);
+    Collection raw2 = new Collection<Integer>(1);
+    Collection raw3 = new Collection<String>("1");
+  }
+}