[Task] Remove "Create a new recovery key" option during sign-in/verification

[mxandreas]

The background is given meta issue.

The summary is that when user lands on the recovery key entrance screen as part of the nominal sign-in / device verification flow, the screen to enter the recovery key should not have the option to "Create a new recovery key". This is already the case in Android but not on iOS.

The official design for reference.