Supported simplest case of signatures propagation in value parameter position.

#KT-2776 in progress

compiler/testData/loadJava/kotlinSignature/propagation/parameter/NotNullToNullable.kt

@@ -0,0 +1,12 @@
+package test
+
+public trait NotNullToNullable: Object {
+
+    public trait Super: Object {
+        public fun foo(p0: String)
+    }
+
+    public trait Sub: Super {
+        override fun foo(p0: String)
+    }
+}