Make sure app has correct SignInType after upgrading

[mchowning]

Warning
I think this PR merits a hotfix, so I have it targeting a new hotfix branch: release/7.37.1.

Description

This avoids scenarios where users migrating from a password SignInType to the token SIgnInType can get stuck in a bad state where the app will always fail to retrieve an updated access token because the app still thought the user was using a password SignInType so it would try to use the stored token as a password, which would fail. This causes the app to present notifications saying the user has been signed out, but the app still indicates the user is signed in apart from this error (and all the API calls would fail).

This PR essentially has two fixes for this issue...

1. d13c31b makes it so that when a user signs in after getting one of these errors, the SignInType is updated appropriately. Before, the SignInType would not get updated because when we called addAccountExplicitly(...) the account already existed. In other words, this makes it so that even if a user gets one of these errors, the issue will be resolved when they sign in.
2. db1fb96 avoids the issue arising in the first place by making sure that any time we store a refresh token instead of a password, we update the SignInType to be Tokens.

This PR also includes some minor improvements to our logging in this area.

Testing Instructions

1. Test that logging in clears the error

1. Install a debugProd build from the 7.36 tag
2. Log into the app
3. Install a debugProd build from the release/7.37.1 branch, applying this patch to make the issue easy to recreate.
4. Tap refresh from the "Profile" tab
5. Observe a sign-in error notification is presented
6. Tap on the sign-in error notification and sign into the same account you signed into on the 7.36 build
7. Observe a new sign-in error notification is presented
8. Install a debugProd build from the first commit in this PR (d13c31b) applying this patch. The reason for using this commit is because it will still allow the error to occur (the fix that avoids the error entirely is db1fb96) and allow you to test that signing in will now fix the error.
9. Install that build
10. Tap refresh from the "Profile" tab
11. Observe there is a sign-in error notification
12. Tap on the error notification and sign into the app using the same account you signed into on the 7.36 build
13. ✅ Observe there is no sign-in error notification and that you can refresh the app from the "Profile" tab without any issues

2. Test that error is avoided entirely

1. Install a debugProd build from the 7.36 tag
2. Log into the app
3. Install a debugProd build from this PR applying [this patch (https://gist.github.com/mchowning/0d4edda7247b536a5abccd20357cebb0).
4. Start the app and perform a refresh.
5. ✅ Observe there are no error notifications

Checklist

• If this is a user-facing change, I have added an entry in CHANGELOG.md
• I have considered whether it makes sense to add tests for my changes

[mchowning]

This doesn't need to be passed because the class already has the SyncServerManager stored as a field.

[ashiagr]

Looks good! It was a tricky one, great job in investigating and providing clear testing steps.