microG does not behave gracefully with invalid sessions of Google accounts

[lucasmz-dev]

Describe the bug
When an user has a Google account logged in, if the session turns invalid (gets logged out remotely for example), many things break in microG and the user is not notified, only leaving the status of certain apps breaking as somewhat of a clue.

To Reproduce
Steps to reproduce the behavior:

1. Log in using a Google account
2. e.g. Google Maps works fine
3. Log out the device out of the Google account remotely via the web online account page (account.google.com)
4. Google Maps does not work properly anymore
5. No notification or other indication that the logged in account isn't a valid session anymore

Expected behavior
microG should automatically detect when a Google account gets logged out and remove the account and potentially warn the user.

Screenshots
If applicable, add screenshots to help explain your problem.

System
Android Version: 14
Custom ROM: CalyxOS 5.14.2
microG version: 0.3.6

Additional context
I notice this as a issue every now and then in the Calyx channels.

[fynngodau]

GMS' behavior is to show a notification, re-prompting the user to enter their password. I intended for this functionality to be added when I wrote this code:

GmsCore/play-services-core/src/main/kotlin/org/microg/gms/accountaction/ErrorResolver.kt

Lines 132 to 133 in 27bacdd

	Log.w(TAG, "Your account credentials have expired! Please remove the account, then sign in again.")
	return null

…but then I didn't get around to implementing it. What is needed in that place is some kind of UI flow that first tells users to reauthenticate using a notification (in the background case) or directly open that page (in the foreground case). Also the background / foreground decision might still be optimized, as so far I only was able to test it for the enterprise account cryptauth flow, which won't occur for all different types of call.

[noaho]

I just had this with Maps, was very confusing because I thought it was due to the latest signature checking changes, but it wasn't (my phone is Jan 2025 L4M build), but actually it was just because I updated my Google password. Maybe this could be a pinned topic?