Update schema before running tests (#4030)

.azure/pipelines/fast-pr-validation.yml

@@ -16,8 +16,8 @@ jobs:
     jobDisplayName: "Build: Windows"
     agentOs: Windows
     beforeBuild:
-    - powershell: "& ./src/IISIntegration/tools/UpdateIISExpressCertificate.ps1"
-      displayName: Setup IISExpress test certificates
+    - powershell: "& ./src/IISIntegration/tools/UpdateIISExpressCertificate.ps1; & ./src/IISIntegration/tools/update_schema.ps1"
+      displayName: Setup IISExpress test certificates and schema
 - template: jobs/iisintegration-job.yml
   parameters:
     TestGroupName: IIS