Fix a few warnings

QuickPlay/MainActivity.cs

@@ -89,7 +89,7 @@ namespace QuickPlay
                     {
                         var i = new Intent("com.google.zxing.client.android.SCAN");
                         StartActivityForResult(i, 0);
-                    } catch (ActivityNotFoundException e) {
+                    } catch (ActivityNotFoundException) {
                         Toast.MakeText(this, "You need ZXing Barcode scanner for this", ToastLength.Long).Show();
                     }
                 });

QuickPlay/QuickPlay.csproj

@@ -42,7 +42,7 @@
     <AndroidEnableProfiledAot>false</AndroidEnableProfiledAot>
     <BundleAssemblies>false</BundleAssemblies>
     <AndroidKeyStore>false</AndroidKeyStore>
-    <AndroidUseAapt2>false</AndroidUseAapt2>
+    <AndroidUseAapt2>true</AndroidUseAapt2>
     <AndroidHttpClientHandlerType>Xamarin.Android.Net.AndroidClientHandler</AndroidHttpClientHandlerType>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">