Refine dirty files computation in case of Java source changes

#KT-17621 In Progress

jps-plugin/testData/incremental/withJava/javaUsedInKotlin/changeSignature/JavaClass.java.new

@@ -1,5 +1,8 @@
 public class JavaClass {
-    public static String foo() {
-        return ":)";
+    public String foo() {
+        return "";
+    }
+
+    public void bar() {
     }
 }