Java to Kotlin converter: and even more smartness about nullability

#KT-5162 Fixed

j2k/tests/testData/ast/nullability/MethodInvokedWithNullArg2.kt

@@ -0,0 +1,10 @@
+class C() {
+    public fun foo(s: String?) {
+    }
+}
+
+class D() {
+    fun bar(c: C) {
+        c.foo(null)
+    }
+}