Update branding to preview4 (#92)

Author: dougbu

eng/Versions.props

@@ -5,7 +5,7 @@
     <MinorVersion>0</MinorVersion>
     <PatchVersion>0</PatchVersion>
     <PreReleaseVersionLabel>preview</PreReleaseVersionLabel>
-    <PreReleaseVersionIteration>3</PreReleaseVersionIteration>
+    <PreReleaseVersionIteration>4</PreReleaseVersionIteration>
     <!--
         When StabilizePackageVersion is set to 'true', this branch will produce stable outputs for 'Shipping' packages
     -->