[Stopwatch] Fix array definition from 5.4

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #7639, #7653
| License       | MIT

I was break tests for 5.3 with my prev. PR #7691