chore(build): fix version placeholder matching

During the `build` task, the version placeholders will be replaced with the actual values using a
RegExp, which expects the placeholders to be surrounded by double quotes. By replacing the quotes
from double to single in #15011, the RegExp was not able to match the placeholders.

(For reference, the RegExps that match and replace the version placeholders are in
[lib/grunt/utils.js][1].)

[1]: https://github.com/angular/angular.js/blob/859348c7f61ff5f93b9f81eb7f46842bd018d8e3/lib/grunt/utils.js#L125-L130

Closes #15016