Fix escape syntax in e2e-tests.yml.jinja workflow

Author: lorenyu

.github/workflows/ci-{{app_name}}-e2e-tests.yml.jinja

@@ -1,4 +1,4 @@
-name: CI {{app_name}} e2e tests
+name: CI {{ app_name }} e2e tests
 
 on:
   # Note: This workflow doesn't run on pull requests. E2E tests on pull requests are
@@ -16,5 +16,5 @@ jobs:
     name: " " # GitHub UI is noisy when calling reusable workflows, so use whitespace for name to reduce noise
     uses: ./.github/workflows/e2e-tests.yml
     with:
-      app_name: "{{app_name}}"
-      service_endpoint: ${{ inputs.service_endpoint }}
+      app_name: "{{ app_name }}"
+      service_endpoint: ${{'{{'}} inputs.service_endpoint {{'}}'}}