Fix template

Author: hectormmg

.pipelines/1p-e2e.yml

@@ -2,8 +2,8 @@ variables:
     CDP_DEFINITION_BUILD_COUNT: $[counter('', 0)] # needed for onebranch.pipeline.version task https://aka.ms/obpipelines/versioning
     LinuxContainerImage: "mcr.microsoft.com/onebranch/cbl-mariner/build:2.0" # Docker image which is used to build the project https://aka.ms/obpipelines/containers
     DEBIAN_FRONTEND: noninteractive
-    sourceBranch: variables['Build.SourceBranch']
-    prSourceBranch: variables['System.PullRequest.SourceBranch']
+    sourceBranch: ${{ variables['Build.SourceBranch'] }}
+    prSourceBranch: ${{ variables['System.PullRequest.SourceBranch'] }}
     ${{ if startsWith(variables['Build.SourceBranch'], 'refs/heads/') }}:
         sourceBranchName: ${{ replace(variables['Build.SourceBranch'], 'refs/heads/', '') }}
     ${{ if startsWith(variables['System.PullRequest.SourceBranch'], 'refs/pull/') }}: