[Xamarin.Android.Tools.AndroidSdk] Check all <intent-filter/>s

[jonpryor]

Context: https://developercommunity.visualstudio.com/t/Cannot-deploy-to-Android-emulators-and-d/10428163
Context: https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1863835
Context: https://developer.android.com/guide/components/intents-filters

The <activity/> and related elements within AndroidManifest.xml can have multiple <intent-filter/>s specified. Android does not require that <intent-filter/>s be listed in any particular order.

However, Visual Studio does care about the order (?!)!

[Activity(Exported = true, Label = "@string/app_name", MainLauncher = true)]
[IntentFilter(
    new[] { Android.Content.Intent.ActionView },
    Categories = new[] {
        Android.Content.Intent.CategoryDefault,
        Android.Content.Intent.CategoryBrowsable,
    }
)]
[IntentFilter(
    new[] { Android.Content.Intent.ActionMain },
    Categories = new[] {
        Android.Content.Intent.CategoryLauncher,
        Android.Content.Intent.CategoryLeanbackLauncher,
    }
)]
public partial class MainActivity : Activity {}

If the [IntentFilter] with Android.Content.Intent.ActionMain is not first, then Visual Studio does not consider this Activity to be a launchable activity.

The reason for this is, in part, because
AndroidAppManifest.GetLaunchableActivities() only looked at the first <intent-filter/> to see if it had the category of android.intent.category.LAUNCHER.

Update AndroidAppManifest.GetLaunchableActivities() so that all <intent-filter/> elements are checked for the
.LAUNCHER category.

Workaround: Specify the [IntentFilter] with Intent.ActionMain first:

[Activity(Exported = true, Label = "@string/app_name", MainLauncher = true)]
[IntentFilter(
    new[] { Android.Content.Intent.ActionMain },
    Categories = new[] {
        Android.Content.Intent.CategoryLauncher,
        Android.Content.Intent.CategoryLeanbackLauncher,
    }
)]
[IntentFilter(
    new[] { Android.Content.Intent.ActionView },
    Categories = new[] {
        Android.Content.Intent.CategoryDefault,
        Android.Content.Intent.CategoryBrowsable,
    }
)]
public partial class MainActivity : Activity {}

Note: this change, in and of itself, may not be sufficient to fix Visual Studio, as there are a few other places that have the same "only check the first <intent-filter/>" bug.