convert all permission string literals in tests to permission constant

[eviljeff]

Follow-on from mozilla/addons#16318

Description

Finishes what I started in mozilla/addons#16318 - to use AclPermission constants in grant_permission calls.

Context

I made the changes to grant_permission; then Claude did the grunt work of converting all the hundreds of references in tests. I've read through them and they seem correct - in almost all test cases the tests would fail if the permissions were wrong anyway.

Testing

n/a - no live code changes.

Checklist

• Add #ISSUENUM at the top of your PR to an existing open issue in the mozilla/addons repository.
• Successfully verified the change locally.
• The change is covered by automated tests, or otherwise indicated why doing so is unnecessary/impossible.
• Add before and after screenshots (Only for changes that impact the UI).
• Add or update relevant docs reflecting the changes made.

[chrstinalin]

Not related to tests, but FYI in src/olympia/abuse/actions.py#312 still uses that join pattern

groups_qs = Group.objects.filter(
            rules__icontains=':'.join(ADDONS_HIGH_IMPACT_APPROVE)
        )

[eviljeff]

Not related to tests, but FYI in src/olympia/abuse/actions.py#312 still uses that join pattern

groups_qs = Group.objects.filter(
            rules__icontains=':'.join(ADDONS_HIGH_IMPACT_APPROVE)
        )

hah, good find. It'll still work (AclPermission remains a tuple) but yeah it can be rules__icontains=str(ADDONS_HIGH_IMPACT_APPROVE) now, or just rules__icontains=ADDONS_HIGH_IMPACT_APPROVE might work, depending on if .filter will convert arg values to str by default.