Linux terminal doesn't work for secondary users' private space

[dot-gov]

It's not possible to enable linux terminal on secondary users, if private space exists and is unlocked. Specifically if you go to settings -> system and try to tap the "linux development environment" item, nothing happens. It works fine if the private space is locked, but that means you can't enable it for private space, only the secondary user. This only happens on secondary users, it works fine on the main user.

Steps to reproduce:

1. as the main user, enable linux terminal in developer settings, and create a secondary user
2. switch to the secondary user
3. create a private space
4. unlock the private space
5. go to settings -> system and try to tap on the "linux development environment" option. You'll see it's not greyed out, but tapping on it doesn't do anything, or show any toasts. Nothing relevant shows up in logcat either.

[dot-gov]

I did some debugging and it looks like it's caused by a combination of:

1. GrapheneOS added a patch to enable linux terminal for secondary users
2. The upstream code has a check that restricts the setting to only when debugging is enabled. Specifically the ProfileSelectLinuxTerminalFragment class implements the DeveloperOptionAwareMixin interface, which the DeveloperOptionsActivityLifecycle checks for, and calls activity.finish() if developer options aren't available. This works fine on the main profile, but breaks on the secondary profile because secondary profile users can't access developer options.
3. There's some additional logic where ProfileSelectLinuxTerminalFragment only gets used if there are multiple profiles enabled and unlocked, otherwise LinuxTerminalDashboardFragment gets used directly. LinuxTerminalDashboardFragment does not have any such checks, which explains why this issue only manifests if the private space is unlocked.

I put in a PR here: GrapheneOS/platform_packages_apps_Settings#397