Support --source-build / -sb switches as well in the VMR (#18492)

src/SourceBuild/content/build.sh

@@ -22,7 +22,7 @@ usage()
   echo ""
 
   echo "Source-only settings:"
-  echo "  --source-only                Source-build the solution (short: -so)"
+  echo "  --source-only, --source-build   Source-build the solution (short: -so, -sb)"
   echo "  --online                        Build using online sources"
   echo "  --poison                        Build with poisoning checks"
   echo "  --release-manifest <FILE>       A JSON file, an alternative source of Source Link metadata"
@@ -117,7 +117,7 @@ while [[ $# > 0 ]]; do
       ;;
 
     # Source-only settings
-    -source-only|-so)
+    -source-only|-source-build|-so|-sb)
       sourceOnly=true
       properties="$properties /p:DotNetBuildSourceOnly=true"
       ;;