Resolves problems found in certification (#424)

Blend renderer showed the wrong title on page

Viewshed for camera had a squished button in some circumstances

Tested on all platforms

src/Forms/Shared/Samples/Analysis/ViewshedCamera/ViewshedCamera.xaml

@@ -1,15 +1,17 @@
 <?xml version="1.0" encoding="utf-8" ?>
 <ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
-             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"             
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
              xmlns:esriUI="clr-namespace:Esri.ArcGISRuntime.Xamarin.Forms;assembly=Esri.ArcGISRuntime.Xamarin.Forms"
              x:Class="ArcGISRuntimeXamarin.Samples.ViewshedCamera.ViewshedCamera">
     <Grid>
-        <esriUI:SceneView x:Name="MySceneView"/>
+        <Grid.RowDefinitions>
+            <RowDefinition Height="*" />
+            <RowDefinition Height="Auto" />
+        </Grid.RowDefinitions>
+        <esriUI:SceneView x:Name="MySceneView" Grid.Row="0" />
         <Button x:Name="UpdateObserverButton"
                 Text="Viewshed from Here"
-                WidthRequest="160" HeightRequest="30"
-                HorizontalOptions="Center" VerticalOptions="Start"
-                Margin="0,5"
-                Clicked="UpdateObserverWithCamera"/>
+                Clicked="UpdateObserverWithCamera"
+                Grid.Row="1" />
     </Grid>
 </ContentPage>

src/Forms/Shared/Samples/Layers/ChangeBlendRenderer/ChangeBlendRenderer.xaml

@@ -3,7 +3,7 @@
              xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
              xmlns:esriUI="clr-namespace:Esri.ArcGISRuntime.Xamarin.Forms;assembly=Esri.ArcGISRuntime.Xamarin.Forms"
     x:Class="ArcGISRuntimeXamarin.Samples.ChangeBlendRenderer.ChangeBlendRenderer"
-             Title="Raster layer (file)">
+             Title="Blend Renderer">
     <Grid>
         <Grid.RowDefinitions>
             <RowDefinition Height="40"/>