ci: sample build in Cloud Build (#1381)

Author: suztomo

.cloudbuild/samples_build.yaml

@@ -0,0 +1,32 @@
+steps:
+- name: gcr.io/cloud-devrel-public-resources/java8
+  entrypoint: ls
+  args: [
+    '-alt',
+  ]
+- name: gcr.io/cloud-devrel-public-resources/java8
+  entrypoint: curl
+  args: [
+    '--header',
+    'Metadata-Flavor: Google',
+    'http://metadata.google.internal/computeMetadata/v1/instance/service-accounts/default/email'
+  ]
+- name: gcr.io/cloud-devrel-public-resources/java8
+  entrypoint: pwd
+- name: gcr.io/cloud-devrel-public-resources/java8
+  entrypoint: bash
+  args: [
+    '.kokoro/build.sh'
+  ]
+  env:
+  - 'JOB_TYPE=samples'
+  - 'GOOGLE_CLOUD_PROJECT=cloud-java-ci-sample'
+  - 'KOKORO_GITHUB_PULL_REQUEST_NUMBER=$_PR_NUMBER'
+- name: gcr.io/cloud-devrel-public-resources/java8
+  entrypoint: echo
+  args: [
+    'Sample job succeeded',
+  ]
+timeout: 3600s
+options:
+  defaultLogsBucketBehavior: REGIONAL_USER_OWNED_BUCKET

samples/snippets/src/test/resources/index.yaml

@@ -12,10 +12,14 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# one time index creation is required to run AggregationQuerySampleTestIT
+# one time index creation is required to run AggregationQuerySampleTestIT and ConceptsTest
 # see https://cloud.google.com/sdk/gcloud/reference/datastore/indexes/create for more details
 indexes:
 - kind: Sales
   properties:
   - name: customerId
   - name: amount
+- kind: Task
+  properties:
+  - name: tag
+  - name: tag