[FEATURE REQUEST] Manage deep links and open the app correctly

[manuelplazaspalacio]

Things to do:

• Adapt AndroidManifest
• Handle intent
• Manage posible login errors
• Check Deep Link correct format.

Expected result: the app is open in login if no user logged and if there is any user logged go to FileDisplayActivity an show success message if correct format.
Spike related: #4068

TASKS

• Research (if needed)
• Create branch feature/feature_name
• Development tasks
  • Open App
  • Manage logged or not logged user
  • Check deep link
• Code review and apply changes requested
• Design test plan
• QA
• Merge branch feature/feature_name into master

QA

Test plan: https://github.com/owncloud/QA/blob/master/Mobile/Android/Feature%20template/Other/Open%20DeepLinks.md

Bugs & improvements:

[jesmrec]

First draft of test plan: https://github.com/owncloud/QA/blob/master/Mobile/Android/Feature%20template/Other/Open%20DeepLinks.md

let me know if you miss something there.