chore(codecommit): migrate tests to use the Assertions module (#18548)

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: skinny85

packages/@aws-cdk/aws-codecommit/package.json

@@ -84,7 +84,7 @@
   },
   "license": "Apache-2.0",
   "devDependencies": {
-    "@aws-cdk/assert-internal": "0.0.0",
+    "@aws-cdk/assertions": "0.0.0",
     "@aws-cdk/aws-sns": "0.0.0",
     "@aws-cdk/cdk-build-tools": "0.0.0",
     "@aws-cdk/cdk-integ-tools": "0.0.0",

packages/@aws-cdk/aws-codecommit/test/codecommit.test.ts

@@ -1,5 +1,5 @@
-import '@aws-cdk/assert-internal/jest';
 import { join, resolve } from 'path';
+import { Template } from '@aws-cdk/assertions';
 import { Role, ServicePrincipal } from '@aws-cdk/aws-iam';
 import { Asset } from '@aws-cdk/aws-s3-assets';
 import * as cxschema from '@aws-cdk/cloud-assembly-schema';
@@ -19,7 +19,7 @@ describe('codecommit', () => {
 
       new Repository(stack, 'MyRepository', props).notify(snsArn);
 
-      expect(stack).toMatchTemplate({
+      Template.fromStack(stack).templateMatches({
         Resources: {
           MyRepository4C4BD5FC: {
             Type: 'AWS::CodeCommit::Repository',
@@ -258,7 +258,7 @@ describe('codecommit', () => {
       repository.grantPullPush(role);
 
       // THEN
-      expect(stack).toHaveResource('AWS::IAM::Policy', {
+      Template.fromStack(stack).hasResourceProperties('AWS::IAM::Policy', {
         PolicyDocument: {
           Statement: [
             {

packages/@aws-cdk/aws-codecommit/test/notification-rule.test.ts

@@ -1,4 +1,4 @@
-import '@aws-cdk/assert-internal/jest';
+import { Template } from '@aws-cdk/assertions';
 import * as sns from '@aws-cdk/aws-sns';
 import * as cdk from '@aws-cdk/core';
 import * as codecommit from '../lib';
@@ -16,7 +16,7 @@ describe('notification rule', () => {
 
     repository.notifyOnPullRequestMerged('NotifyOnPullRequestMerged', target);
 
-    expect(stack).toHaveResource('AWS::CodeStarNotifications::NotificationRule', {
+    Template.fromStack(stack).hasResourceProperties('AWS::CodeStarNotifications::NotificationRule', {
       Name: 'MyCodecommitRepositoryNotifyOnPullRequestCreatedBB14EA32',
       DetailType: 'FULL',
       EventTypeIds: [
@@ -38,7 +38,7 @@ describe('notification rule', () => {
       ],
     });
 
-    expect(stack).toHaveResource('AWS::CodeStarNotifications::NotificationRule', {
+    Template.fromStack(stack).hasResourceProperties('AWS::CodeStarNotifications::NotificationRule', {
       Name: 'MyCodecommitRepositoryNotifyOnPullRequestMerged34A7EDF1',
       DetailType: 'FULL',
       EventTypeIds: [