[SG-396] Fix tappable area after hiding account switching on Autofill

[fedemkr]

Type of change

• Bug fix
• New feature development
• Tech debt (refactoring, code cleanup, dependency upgrades, etc)
• Build/deploy pipeline (DevOps)
• Other

Objective

On Autofill, after hiding the account switching overlay the user can't select any items. So this fixes the tap area.

Code changes

• AccountSwitchingOverlayView.xaml.cs: Added AfterHide action to invoke after hiding the account switching overlay
• AccountSwitchingOverlayHelper.cs: Hide the container of the account switching overlay after the overlay hidden animation finishes. Fix one tiny animation issue when displaying the overlay

Before you submit

• I have checked for formatting errors (dotnet tool run dotnet-format --check) (required)
• I have added unit tests where it makes sense to do so (encouraged but not required)
• This change requires a documentation update (notify the documentation team)
• This change has particular deployment requirements (notify the DevOps team)