Use expansion in a variable

Author: Evangelink

azure-pipelines-official.yml

@@ -62,6 +62,8 @@ variables:
     value: ''
   - name: _BuildConfig
     value: Release
+  - name: _Products
+    value: ${{parameters.products}}
 
   - ${{ if eq(parameters.isRTM, True) }}:
     - name: _ReleaseVersionKind
@@ -82,7 +84,7 @@ variables:
       /p:DotNetSymbolServerTokenMsdl=$(microsoft-symbol-server-pat)
       /p:DotNetSymbolServerTokenSymWeb=$(symweb-symbol-server-pat)
       /p:OfficialBuildId=$(BUILD.BUILDNUMBER)
-      /p:ProductsToBuild=${{parameters.products}}
+      /p:ProductsToBuild=$(_Products)
 
 resources:
   repositories: