Add YAML test for non-build-gcs GCS resource

This test fetches a publicly-visible zip archive object from GCS, unzips
it and reads the file it expects to find within.

examples/taskruns/gcs-resource.yaml

@@ -0,0 +1,25 @@
+apiVersion: tekton.dev/v1alpha1
+kind: TaskRun
+metadata:
+ name: gcs-resource
+spec:
+ taskSpec:
+ inputs:
+ resources:
+ - name: source
+ type: storage
+ steps:
+ - image: alpine
+ command: ['unzip', 'source/archive.zip']
+ - image: alpine
+ command: ['cat', 'file.txt']
+ inputs:
+ resources:
+ - name: source
+ resourceSpec:
+ type: storage
+ params:
+ - name: location
+ value: gs://build-crd-tests/archive.zip
+ - name: type
+ value: gcs