Revert "Remove source-build workaround for sourcelink submodule issue (#39324)" (#39356)

This reverts commit 9b049bd.

Author: MichaelSimons

eng/SourceBuild.props

@@ -3,6 +3,7 @@
   <PropertyGroup>
     <GitHubRepositoryName>aspnetcore</GitHubRepositoryName>
     <SourceBuildManagedOnly>true</SourceBuildManagedOnly>
+    <CloneSubmodulesToInnerSourceBuildRepo>false</CloneSubmodulesToInnerSourceBuildRepo>
   </PropertyGroup>
 
   <Target Name="PrepareGlobalJsonForSourceBuild"
@@ -13,6 +14,19 @@
       WorkingDirectory="$(InnerSourceBuildRepoRoot)" />
   </Target>
 
+  <!--
+    Init submodules - temporarary workaround for https://github.com/dotnet/sourcelink/pull/653
+  -->
+  <Target Name="InitSubmodules"
+          DependsOnTargets="PrepareInnerSourceBuildRepoRoot"
+          BeforeTargets="RunInnerSourceBuildCommand">
+
+    <Exec
+      Command="git submodule update --init --recursive"
+      WorkingDirectory="$(InnerSourceBuildRepoRoot)"
+      EnvironmentVariables="@(InnerBuildEnv)" />
+  </Target>
+
   <!--
     Remove inner source .globalconfig file as both the inner and outer config files get loaded and cause a conflict.
     Leaving the inner will cause all conflicting settings to be ignored.