[Process] Fixed issue where $env or $_ENV can contain array values

See Ticket #7196 

[Process] Fixed issue where $env or $_ENV can contain array values

```
| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | 7196
| License       | MIT
| Doc PR        | none
```