Shorten array syntax

```
Bug fix: no
Feature addition: no
Backwards compatibility break: no
Unit test passes: yes
Specs passes: yes
Replaced unit test classes removed: no
Behat scenario passes: ?
Checkstyle issues: ?
ChangeLog updated: no
Documentation PR: 
Fixes the following jira:
```

This is a consitency purpose PR.
It was achieved with https://github.com/thomasbachem/php-short-array-syntax-converter.