Cleaned minor usings

Author: jfversluis

Xamarin.Forms.Material.Android/MaterialButtonRenderer.cs

@@ -17,7 +17,6 @@
 using AView = Android.Views.View;
 using MButton = Android.Support.Design.Button.MaterialButton;
 using Xamarin.Forms.Platform.Android;
-using AButton = Android.Widget.Button;
 
 namespace Xamarin.Forms.Material.Android
 {

Xamarin.Forms.Platform.Android/AppCompat/ButtonRenderer.cs

@@ -6,11 +6,9 @@
 using Android.Util;
 using Android.Views;
 using Xamarin.Forms.Platform.Android.FastRenderers;
-using Xamarin.Forms.Internals;
 using Xamarin.Forms.PlatformConfiguration.AndroidSpecific;
 using AColor = Android.Graphics.Color;
 using AView = Android.Views.View;
-using AButton = Android.Widget.Button;
 
 namespace Xamarin.Forms.Platform.Android.AppCompat
 {

Xamarin.Forms.Platform.Android/AppCompat/RadioButtonRenderer.cs

@@ -11,8 +11,6 @@
 using Xamarin.Forms.PlatformConfiguration.AndroidSpecific;
 using AColor = Android.Graphics.Color;
 using AView = Android.Views.View;
-using AWidget = Android.Widget;
-using AButton = Android.Widget.Button;
 using Android.Graphics.Drawables;
 using Android.Widget;
 

Xamarin.Forms.Platform.Android/ButtonLayoutManager.cs

@@ -53,7 +53,7 @@ public ButtonLayoutManager(IButtonLayoutRenderer renderer,
 			_borderAdjustsPadding = borderAdjustsPadding;
 			_maintainLegacyMeasurements = maintainLegacyMeasurements;
 		}
-		
+
 		AButton View => _renderer?.View ?? _renderer as AButton;
 
 		Context Context => _renderer?.View?.Context;