test: fix e2e test failures due to upstream change (#715)

Author: sdowell

examples/gatekeeper-disallow-root-user/.expected/results.yaml

@@ -5,7 +5,7 @@ metadata:
 exitCode: 1
 items:
   - image: gcr.io/kpt-fn/gatekeeper:unstable
-    stderr: |
+    stderr: |-
       [error] apps/v1/Deployment/nginx-deploy : Containers must not run as root
       violatedConstraint: disallowroot
     exitCode: 1

examples/gatekeeper-imperative/.expected/results.yaml

@@ -5,7 +5,7 @@ metadata:
 exitCode: 1
 items:
   - image: gcr.io/kpt-fn/gatekeeper:unstable
-    stderr: |
+    stderr: |-
       [error] v1/ConfigMap/default/super-secret : The following banned keys are being used in the ConfigMap: {"private_key"}
       violatedConstraint: no-secrets-in-configmap
     exitCode: 1

examples/gatekeeper-invalid-configmap/.expected/results.yaml

@@ -5,7 +5,7 @@ metadata:
 exitCode: 1
 items:
   - image: gcr.io/kpt-fn/gatekeeper:unstable
-    stderr: |
+    stderr: |-
       [error] v1/ConfigMap/default/super-secret : The following banned keys are being used in the ConfigMap: {"private_key"}
       violatedConstraint: no-secrets-in-configmap
     exitCode: 1

tests/gatekeeper/v1beta1-template/.expected/results.yaml

@@ -5,7 +5,7 @@ metadata:
 exitCode: 1
 items:
   - image: gcr.io/kpt-fn/gatekeeper:unstable
-    stderr: |
+    stderr: |-
       [error] apps/v1/Deployment/nginx-deploy : Containers must not run as root
       violatedConstraint: disallowroot
     exitCode: 1

tests/starlark/non-standard-features/.expected/results.yaml

@@ -5,7 +5,7 @@ metadata:
 exitCode: 0
 items:
   - image: gcr.io/kpt-fn/starlark:unstable
-    stderr: |
+    stderr: |-
       set(["foo", "bar"])
       2
     exitCode: 0