Before this, we were using `is_user_in_setting_group` which does not do
the extra checks around a guest user's permissions (and in future, some
other checks).
We introduced `initialize_and_override_current_user` in stream_data test
to make it easier to set current_user.user_id.
We are making this change with default set as true, since that is the
behaviour other functions are expecting. We are not making any behaviour
changes in this commit on where metadata access should be check or where
content access should be checked for this function's usage. That will be
done commit by commit for different functions using
`can_change_permissions`.
Accepting `require_content_access` makes it a bit hard to read at other
places where the argument is passed as just true or false without
knowing what the argument is for, but it was just a choice when writing
the code. We will refactor this current function into two functions in
the upcoming commits and solve that problem.
We've also removed `can_edit_description` from `stream_data` but we have
kept around `can_change_name_description` in `stream_settings_data`.
Since `can_edit_description` was just used at once place, it didn't make
much sense to keep it around, but we kep around
`can_change_name_description` since we've already done the work to have
fine tuned permissions for that setting and we don't want to undo that
work.
