fix diagnostic name

[bavardage]

Before this PR

Reporting the wrong diagnostic name in manifest extension

After this PR

==COMMIT_MSG== Fix the heap stats diagnostic name in manifest extension ==COMMIT_MSG==

[changelog-app[bot]]

Generate changelog in changelog-dir>`changelog/@unreleased`</changelog-dir

Type

- [ ] Feature - [ ] Improvement - [x] Fix - [ ] Break - [ ] Deprecation - [ ] Manual task - [ ] Migration

Description

Fix the heap stats diagnostic name in manifest extension **Check the box to generate changelog(s)** - [x] Generate changelog entry