Allow sharing on user-mounted external storages is not been taking into account

[davitol]

Steps to reproduce

1. As admin run occ command occ user:add davitol --email davitol@mymail.es

Expected behaviour

Users cannot share / decide the content of its Personal Mounts

Actual behaviour

Users are able to decide if they can share or not the Personal mount content.

Server configuration

Operating system:
Ubuntu 18.04
Web server:
Apache2
Database:
MySQL
PHP version:
7.2
ownCloud version: (see ownCloud admin page)
10.0.10
Updated from an older ownCloud or fresh install:
fresh

[ownclouders]

GitMate.io thinks the contributor most likely able to help you is @phil-davis.

Possibly related issues are #23536 (Cannot share external storage mount points), #10198 (External Only Storage), #23348 (External storage sharing options not easily found), #25107 (Can't share files on external storage "Re sharing is not allowed"), and #18717 (Sharing on external storage not allowed (user is not in an excluded group)).