Update Versions.props to build 7.3.0-preview.1 packages

Author: kevinchalet

eng/Versions.props

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <MajorVersion>7</MajorVersion>
-    <MinorVersion>2</MinorVersion>
+    <MinorVersion>3</MinorVersion>
     <PatchVersion>0</PatchVersion>
     <VersionPrefix>$(MajorVersion).$(MinorVersion).$(PatchVersion)</VersionPrefix>
     <PreReleaseVersionLabel>preview</PreReleaseVersionLabel>