Update main branding to preview2 (#64219)

eng/Versions.props

@@ -7,8 +7,8 @@
     <MinorVersion>0</MinorVersion>
     <PatchVersion>0</PatchVersion>
     <SdkBandVersion>7.0.100</SdkBandVersion>
-    <PreReleaseVersionLabel>alpha</PreReleaseVersionLabel>
-    <PreReleaseVersionIteration>1</PreReleaseVersionIteration>
+    <PreReleaseVersionLabel>preview</PreReleaseVersionLabel>
+    <PreReleaseVersionIteration>2</PreReleaseVersionIteration>
     <!-- Set assembly version to align with major and minor version,
          as for the patches and revisions should be manually updated per assembly if it is serviced. -->
     <AssemblyVersion>$(MajorVersion).$(MinorVersion).0.0</AssemblyVersion>