Java to Kotlin converter: replacing equals call to ==/!= and no redundant parethesis generation

#KT-4426 Fixed

j2k/tests/testData/ast/equals/Equals3.java

@@ -0,0 +1,10 @@
+//file
+class C{
+    public boolean equals(C c) {
+        return false;
+    }
+
+    boolean foo(C c1, C c2) {
+        return c1.equals(c2)
+    }
+}