Add pool env variable to build-test-resource-config template

Author: benbp

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

@@ -97,9 +97,11 @@ jobs:
           parameters:
             SubscriptionConfiguration: ${{ parameters.CloudConfig.SubscriptionConfiguration }}
             SubscriptionConfigurations: ${{ parameters.CloudConfig.SubscriptionConfigurations }}
-            EnvVars: ${{ parameters.EnvVars }}
             ${{ if eq('true', parameters.UseFederatedAuth) }}:
               SubscriptionConfigurationFilePaths: ${{ parameters.CloudConfig.SubscriptionConfigurationFilePaths }}
+            EnvVars:
+              Pool: $(Pool)
+              ${{ insert }}: ${{ parameters.EnvVars }}
 
         - ${{ if parameters.TestResourceDirectories }}:
           - ${{ each directory in parameters.TestResourceDirectories }}: