[A] Fix insights api key access for Legacy Android

Xamarin.Forms.ControlGallery.Android/Activity1.cs

@@ -188,7 +188,7 @@ namespace Xamarin.Forms.ControlGallery.Android
 			base.OnCreate(bundle);
 
 			if (!Debugger.IsAttached)
-				Insights.Initialize(App.InsightsApiKey, this.ApplicationContext);
+				Insights.Initialize(App.Secrets["InsightsApiKey"], this.ApplicationContext);
 
 			Forms.Init(this, bundle);
 			FormsMaps.Init(this, bundle);