Mitigate the Microsoft account login

[jsauvexamarin]

( Originally opened by @dvdsgl )

The first experience of using this Xamarin app is:

1. Memorize credentials on the first screen and press Sign In. (It's not clear that I am supposed to remember these, it just looks like a broken login form that cannot be edited.)
2. Enter the credentials if you remember them and press Sign In again.

This is a bad first experience for someone checking out Xamarin. The interaction is bad and the presentation of a web view is bad and contradicts our native UI message.

Potential Fixes

• Can we just post to the Azure login form directly, and use a native login UI?
• If not, can we use JavaScript to pre-fill the username and password fields?
• Can we create a build of this app that hard-codes an access key, so we can skip the Azure bit and let users focus on Xamarin as a native cross-platfrom app product and not an Azure client product?

I understand @stevenyix's desire to show how Azure should be used, and clearly very many customers desire and benefit from this, but as long as MobileCRM is our latest and greatest sample app, I am certain that this clunky web-based login flow is the wrong way to introduce people to Xamarin.

[jsauvexamarin]

I agree that MSFT's OAuth login web view is clunky and cumbersome. This is usually the case with most OAuth login UIs: they're generally web-based, unless the OAuth provider publishes a native library for rendering a native UI. The idea being, of course, that the developer of the app is never allowed to touch the user's credentials. So, we'll have to work together to find a better solution. In the meantime, we plan to update the splash screen to have two buttons: one that navigates to the OAuth login and demonstrates that process for enterprise customers, and another that allows users to completely bypass that step and get right into the app. We're not using the returned token for any subsequent requests right now anyway, so that should be fine from a technical standpoint.