Prevent exposing private super interfaces when producing framework

#KT-21819 Fixed

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/objcexport/ObjCExportHeaderGenerator.kt

@@ -145,7 +145,7 @@ internal class ObjCExportHeaderGenerator(val context: Context) {
     }
 
     private val ClassDescriptor.superProtocolsClause: String get() {
-        val interfaces = this.getSuperInterfaces()
+        val interfaces = this.getSuperInterfaces().filter { mapper.shouldBeExposed(it) }
         return if (interfaces.isEmpty()) {
             ""
         } else buildString {