Add pool env variable to build-test-resource-config template (#5749)

Author: benbp

eng/pipelines/templates/jobs/live.tests.yml

@@ -154,6 +154,8 @@ jobs:
     parameters:
       SubscriptionConfiguration: ${{ parameters.CloudConfig.SubscriptionConfiguration }}
       SubscriptionConfigurations: ${{ parameters.CloudConfig.SubscriptionConfigurations }}
+      EnvVars:
+        Pool: $(Pool)
 
   - template: /eng/common/TestResources/deploy-test-resources.yml
     parameters: