UX Polish

[johnkmzhou]

• Mark agendas that already have submitted testimonies.
• On the video upload modal, should Back To Agenda Items button appear while uploading or after?
• Due to processes, the duplicate testimony error modal will appear right after the uploading modal. Should this be the case?
• Reminder that clicking on a tab again should clear the entire nav stack.

[johnkmzhou]

Do screens need back buttons? If so should the header for the back button be fixed on the screen?