Multiple users are [now enabled for all devices in
`device_phh_treble`][1], therefore the multi user settings aren't
necessary in hardware overlays anymore. Therefore this commit removes
and blacklists the `config_enableMultiUserUI` and
`config_multiuserMaximumUsers`.
Please mind that this enables the multi user UI for some devices from
Huawei and Infinix which had it actively disabled previously. However
those devices had set a maximum number of users larger than one, which
might suggest the disabled UI isn't related to device specific
limitations, but to a copy & paste error instead.
[1]: 93335b6e59/overlay/frameworks/base/core/res/res/values/config.xml (L27-L28)
b51f925dc3