Extract Function: Limit the set of allowed containers for the default action

idea/testData/refactoring/extractFunction/defaultContainer/classFunction.kt

@@ -0,0 +1,7 @@
+class A {
+    class B {
+        fun foo(a: Int, b: Int): Int {
+            return <selection>a + b - 1</selection>
+        }
+    }
+}