feat(@angular/cli): log number of files update during ng update

This commit updates `ng update` to include the number of files updated when a migration is completed.

Closes #24488

packages/angular/cli/src/commands/update/cli.ts

@@ -387,16 +387,29 @@ export class UpdateCommandModule extends CommandModule<UpdateCommandArgs> {
  logger.info(' ' + description.join('.\n '));
  }
 
- const result = await this.executeSchematic(
+ const { success, files } = await this.executeSchematic(
  workflow,
  migration.collection.name,
  migration.name,
  );
- if (!result.success) {
+ if (!success) {
  return 1;
  }
 
- logger.info(' Migration completed.');
+ let modifiedFilesText: string;
+ switch (files.size) {
+ case 0:
+ modifiedFilesText = 'No changes made';
+ break;
+ case 1:
+ modifiedFilesText = '1 file modified';
+ break;
+ default:
+ modifiedFilesText = `${files.size} files modified`;
+ break;
+ }
+
+ logger.info(` Migration completed (${modifiedFilesText}).`);
 
  // Commit migration
  if (commit) {