ArcadeBuildFromSource -> DotNetBuildSourceOnly (#58423)

* ArcadeBuildFromSource -> DotNetBuildSourceOnly

* Fix submodule

Author: mmitche

eng/DotNetBuild.props

@@ -103,7 +103,7 @@
 
     <PropertyGroup>
       <!-- Disable installing puppeteer browsers when running in source build -->
-      <_AdditionalEnvironmentVariable Condition="$(ArcadeBuildFromSource) == 'true'">PUPPETEER_SKIP_DOWNLOAD=1</_AdditionalEnvironmentVariable>
+      <_AdditionalEnvironmentVariable Condition="$(DotNetBuildSourceOnly) == 'true'">PUPPETEER_SKIP_DOWNLOAD=1</_AdditionalEnvironmentVariable>
     </PropertyGroup>
 
     <Exec