Yalp/F-Droid / system apps non-update

(Issue title)

Summary

When Yalp and/or F-Droid are installed, they show updates to apps that are system apps in /e/ such as QKSMS, Tasks, Telegram and (Fake) Google Play Store. They cannot be updated. As such, this behaviour makes perfectly sense, and it is not a bug, but it is likely to cause trouble to less expertienced users. I believe many people will install Yalp to access already paid apps, therefore it would be good that /e/s system apps do not appear as upgradable in Yalp and F-Droid to avoid confusion. Especially with regards to the (Fake) Google Play Store this will be important as users might not understand why Google Play Store should be updated on a Gxxxle-free system.

Steps to reproduce

Install /e/
Install Yalp and/or F-Droid app(s)

What is the current behavior?

In Yalp and/or F-Droid updates for system relevant apps from /e/ are shown but not updated (error message).

What is the expected correct behavior?

Ideally, system relevant apps are not shown displayed for update, neither in Yalp, F-Droid nor similar apps.

Relevant logs and/or screenshots

Possible fixes

(If you can, link to the line of code that might be the cause for this problem)