Add passcode functionality to skunkworks-crow

1. What is the general goal of the feature?
currently, while sharing of forms in skunkworks we will directly head to share the forms but, assume the scenario that if any user has some important details in forms and it should not has to be shared so, may someone using skunkworks-crow will share the forms so, it is not the good behavior of app so, I want to add the feature that while opening the app user has to enter the passcode to enter the app

How it will affect users
By, adding this feature user can have some security that he can share the forms whoever he wants

Additional Information
If any user wants this feature he has to download another app which provides him the functionality to lock the app and in some phones, there is an inbuilt feature to lock the app
but in most of the phones which android version lesser than 8 do not have this feature so, user have to download another app so, it is not good behavior
We can give the option that if user wants he can enable that feature

@LN @dexter21 @Shobhit_Agarwal, please give your opinions here :smile:

Copying the response from the slack.

For Locking the app or to secure the data there are a lot of apps, we should not be focusing on these solutions
its not ODK's main objective

If required we can do this in the future, but for now, I don't think it will be helpful