Update branding to 2.1.5 (dotnet#19484)

Author: mmitche

dependencies.props

@@ -12,7 +12,7 @@
 
   <PropertyGroup>
     <!-- Central place to set the versions of all nuget packages produced in the repo -->
-    <PackageVersion Condition="'$(PackageVersion)' == ''">2.1.3</PackageVersion>
+    <PackageVersion Condition="'$(PackageVersion)' == ''">2.1.5</PackageVersion>
 
     <!-- Set the boolean below to true to generate packages with stabilized versions -->
     <StabilizePackageVersion Condition="'$(StabilizePackageVersion)' == ''">false</StabilizePackageVersion>