Ensured that reference to eShopOnContainers.Core is present in all projects.

Author: David Britch

src/Mobile/eShopOnContainers/eShopOnContainers.Droid/Resources/Resource.Designer.cs

@@ -18,7 +18,7 @@
     <GenerateSerializationAssemblies>Off</GenerateSerializationAssemblies>
     <AndroidManifest>Properties\AndroidManifest.xml</AndroidManifest>
     <AndroidUseLatestPlatformSdk>true</AndroidUseLatestPlatformSdk>
-    <TargetFrameworkVersion>v7.1</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v8.0</TargetFrameworkVersion>
     <AndroidSupportedAbis>armeabi,armeabi-v7a,x86</AndroidSupportedAbis>
     <AndroidStoreUncompressedFileExtensions />
     <MandroidI18n />