Installer doesn't show partitions on MacBook

### What Happened?

Same issue as #617 that issue should not have been closed, as it is not fixed with the new commit.

### Steps to Reproduce

1. Booted into Live Demo Mode
2. Added ppa:elementary-os/daily
3. apt update
4. apt install io.elementary.installer
5. io.elementary.installer
6. Can use the installer up to the part where i click Erase Entire Disk

### Expected Behavior

Should be able to select Install and Erase Entire disk, but it doesn't show any partitions.

### OS Version

7.x (Horus)

### Software Version

Latest release (I have run all updates)

### Log Output

```shell
** (io.elementary.installer:9521): CRITICAL **: 07:20:11.347: CheckView.vala:105: Unable to get disks list: GDBus.Error:org.freedesktop.DBus.Error.NoReply: Message recipient disconnected from message bus without replying
```

### Hardware Info

MacBook 12" Retina (2017)