Autofill management: Better state handling

[karlenDimla]

Task/Issue URL: https://app.asana.com/0/488551667048375/1202659292537112/f

Description

This PR includes:

• Adding support to launch edit mode directly through viewmodel
• Adding support to launch view mode autofill credential management
• Fixing handling for config chnages / backgrounding for credential mode

Steps to test this PR

Autofill management works as expected!

• [ ] Save a few credentials
• [ ] Open management through overflow and settings.
• [ ] Verify that list mode is shown as expected.
• [ ] Open a credential.
• [ ] Verify that credential mode is displayed with correct values and aligned to design.
• [ ] Select edit from context menu.
• [ ] Verify that edit mode is displayed with correct values and aligned to design.
• [ ] Press back. Verify that back button works as expected all the way to exiting the management screen.
• [ ] Repeat the steps above and try saving in edit mode.
• [ ] Verify that user is returned to view mode with saved values updated.
• [ ] Repeat the steps above and try deleting. Verify that it works as expected.

Handling back/config changes

• [ ] Save a few credentials
• [ ] In list mode, try backgrounding app and changing config. Verify that state is retained correctly.
• [ ] Press back and verify that backstack is as expected.
• [ ] Go to credential view mode. Try backgrounding app and changing config. Verify that state is retained correctly.
• [ ] Press back and verify that backstack is as expected.
• [ ] Go to credential edit mode. Try backgrounding app and changing config. Verify that state is retained correctly.
• [ ] Press back and verify that backstack is as expected.
• [ ] In all pages, try backgrounding the app and cancelling the device auth. Verify that autofill management is exited.