C#/Java: Rename the directories containing the model generator and tests.

java/ql/test/utils/modelgenerator/dataflow/p/FinalClass.java

@@ -0,0 +1,15 @@
+package p;
+
+public final class FinalClass {
+
+    private static final String C = "constant";
+
+    public String returnsInput(String input) {
+        return input;
+    }
+
+    public String returnsConstant() {
+        return C;
+    }
+
+}