update unit tests to match new generated outputs

packages/pigeon/test/kotlin_generator_test.dart

@@ -129,13 +129,13 @@ void main() {
     expect(code, contains('''
         if (api != null) {
           channel.setMessageHandler { message, reply ->
-            val wrapped = hashMapOf<String, Any?>()
+            val wrapped = mutableListOf<Any?>()
             try {
               val args = message as List<Any?>
               val inputArg = args[0] as Input
-              wrapped["result"] = api.doSomething(inputArg)
+              wrapped.add(api.doSomething(inputArg))
             } catch (exception: Error) {
-              wrapped["error"] = wrapError(exception)
+              wrapped.add(wrapError(exception))
             }
             reply.reply(wrapped)
           }

packages/pigeon/test/objc_generator_test.dart

@@ -107,10 +107,7 @@ void main() {
     final String code = sink.toString();
     expect(code, contains('#import "foo.h"'));
     expect(code, contains('@implementation Foobar'));
-    expect(
-        code,
-        contains(
-            'pigeonResult.enum1 = [GetNullableObject(dict, @"enum1") integerValue];'));
+    expect(code, contains('pigeonResult.enum1 = [list[1] integerValue];'));
   });
 
   test('primitive enum host', () {
@@ -347,8 +344,7 @@ void main() {
     generateObjcSource(const ObjcOptions(header: 'foo.h'), root, sink);
     final String code = sink.toString();
     expect(code, contains('@implementation Foobar'));
-    expect(code,
-        contains('pigeonResult.aBool = GetNullableObject(dict, @"aBool");'));
+    expect(code, contains('pigeonResult.aBool = list[0];'));
   });
 
   test('nested class header', () {
@@ -390,8 +386,11 @@ void main() {
     expect(
         code,
         contains(
-            'pigeonResult.nested = [Input nullableFromMap:GetNullableObject(dict, @"nested")];'));
-    expect(code, matches('[self.nested toMap].*@"nested"'));
+            'pigeonResult.nested = [Input fromList:[list objectAtIndex:0 ]];'));
+    expect(
+        code,
+        contains(
+            '[list addObject:(self.nested ? [self.nested toList] : [NSNull null])]'));
   });
 
   test('prefix class header', () {
@@ -489,7 +488,7 @@ void main() {
     final StringBuffer sink = StringBuffer();
     generateObjcSource(const ObjcOptions(prefix: 'ABC'), root, sink);
     final String code = sink.toString();
-    expect(code, contains('ABCInput fromMap'));
+    expect(code, contains('ABCInput fromList'));
     expect(code, matches(r'ABCInput.*=.*args.*0.*\;'));
     expect(code, contains('void ABCApiSetup('));
   });