WIP implementation for the app unlock flow when called from Passkey

[dinisvieira]

Type of change

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

Objective

• Implement Unlock flow when launched from Passkey
• Make sure Window workarounds on Android work

Code changes

• WIP implementation for the app unlock flow when called from Passkey.
• Also added a new Window workaround in App.xaml.cs to allow CredentialProviderSelectionActivity.cs to launch separately.

TODO

• Organize code in DeviceActionService.cs into some place where it can be shared with CredentialProviderService.cs
• Method ReturnToPasskeyAfterUnlock() (in DeviceActionService.cs) can possibly be moved somewhere else also?

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