Update Google SDK version to 561

Author: AaronMT

taskcluster/docker/ui-tests/Dockerfile

@@ -14,7 +14,7 @@ RUN apt-get install -y jq \
 USER worker:worker
 
 ENV GOOGLE_SDK_DOWNLOAD ./gcloud.tar.gz
-ENV GOOGLE_SDK_VERSION 529
+ENV GOOGLE_SDK_VERSION 561
 
 ENV TEST_TOOLS /builds/worker/test-tools
 ENV PATH ${PATH}:${TEST_TOOLS}:${TEST_TOOLS}/google-cloud-sdk/bin