18-Move_answer_button_to_actionbar

Description

As discussed in https://gitlab.e.foundation/e/backlog/-/issues/4723#note_170115, Move the message answer button to actionBar from headerView. as discussed

Issue(s)

• https://gitlab.e.foundation/e/os/backlog/-/issues/18

Test environment

Download apk from https://gitlab.e.foundation/e/apps/mail/-/jobs/269344/artifacts/file/app/k9mail/build/outputs/apk/debug/k9mail-debug.apk, install it in your device

Test procedures

Open mail app, open any mail, check the answer button is in the actionBar instead of top section of the mail details body.

Technical details

• show actionBar's send button showAsAction=always as its already serve the same purpose, but hidden behind 3 dots buttons.

• set message_view_header.xml's icon_single_message_options visibility to invisible. Doesn't set it to gone, as other views (example sender text) have constrained set to it.

Screenshots

light	dark

Check list

• Self review
• Test procedure explained
• Tested on fresh install
• Tested applied as an update
• License
• Internal documentation
• User documentation

Closes #21