Add change log. Fix spec.

changelogs/unreleased/fix-sm-37559-pipeline-triggered-through-api-not-showing-trigger-variables.yml

+---
+title: Fix Pipeline Triggers to show triggered label and predefined variables (e.g.
+  CI_PIPELINE_TRIGGERED)
+merge_request: 14244
+author:
+type: fixed

spec/services/ci/pipeline_trigger_service_spec.rb

@@ -34,7 +34,7 @@ describe Ci::PipelineTriggerService do
           expect(result[:pipeline].ref).to eq('master')
           expect(result[:pipeline].project).to eq(project)
           expect(result[:pipeline].user).to eq(trigger.owner)
-          expect([result[:pipeline].trigger_requests.last])
+          expect(result[:pipeline].trigger_requests.to_a)
             .to eq(result[:pipeline].builds.map(&:trigger_request).uniq)
           expect(result[:status]).to eq(:success)
         end