[Gekidou] Custom Navigation header alignment (#6172)
[Gekidou] Custom Navigation header alignment (#6172)

* Custom Navigation bar alignment

* Center title & subtitle on iOS
mattermost/mattermost-mobile,mattermost/mattermost-mobile,mattermost/mattermost-mobile,mattermost/mattermost-mobile,mattermost/mattermost-mobile,mattermost/mattermost-mobile,mattermost/mattermost-mobile,mattermost/mattermost-mobile,mattermost/mattermost-mobile,mattermost/mattermost-mobile