Busy status missing from selectable options

[nickvergessen]

@sowjanyakch please have a look

[nickvergessen]

Also make sure the colors are the same as in nextcloud/files-clients#103 (comment)
And the descriptions of the statuses match the web version

[AndyScherzinger]

You also might want to check out nextcloud/android#15441 where @tobiasKaminsky already did the change as discussed with designers for the Files client.