ci: add explicit symbol upload (#424)

Author: calebkiage

.azure-pipelines/ci-build.yml

@@ -268,6 +268,6 @@ stages:
                               displayName: "NuGet push"
                               inputs:
                                   command: push
-                                  packagesToPush: "$(Pipeline.Workspace)/Nugets/Microsoft.Graph.Cli.Core.*.nupkg"
+                                  packagesToPush: "$(Pipeline.Workspace)/Nugets/Microsoft.Graph.Cli.Core.*.nupkg;$(Pipeline.Workspace)/Nugets/Microsoft.Graph.Cli.Core.*.snupkg"
                                   nuGetFeedType: external
                                   publishFeedCredentials: "microsoftgraph NuGet connection"