Previously `karma-coverage` was validated only when in karma plugins config one of these was added
``'karma-coverage'` or `require('karma-coverage')`
This change will allow cli to validate `karma-coverage` plugin if in `karma.conf.js` `'karma-*'` is used. Example:
```
plugins: [
...
'karma-*',
require('@angular-devkit/build-angular/plugins/karma'),
...
]
```
Fixes#19993