[native] fix indexing in tag channel button action sheet

Summary: As I am working on bringing the channel tagging UI to web, I noticed that the indexing in the tag channel button action sheet was broken. In D11894, I got some feedback to make "Other" appear first rather than at the end. I addressed this feedback; however, I forgot to update the indexing to handle this change, so every option was off by one. This diff should fix this issue

Test Plan: Confirmed that the indexing for tag channel button action sheet works as expected

Reviewers: inka, kamil

Reviewed By: inka

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D12540