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

#KT-4426 Fixed

j2k/tests/testData/ast/prefixOperator/kt-667.kt

@@ -1,2 +1,2 @@
-val i = (10).inv()
-val j = ((i * 100)).inv()
+val i = 10.inv()
+val j = (i * 100).inv()

j2k/tests/testData/ast/prefixOperator/tilde.kt

@@ -1,2 +1,2 @@
 val i = 10
-val j = (10).inv()
+val j = 10.inv()