Skip the bigtable test until it's fixed.
Skip the bigtable test until it's fixed.

Change-Id: I3f3fba9dba45b326bbd9bdfebf00a2fd57798dc3

GoogleCloudPlatform/dotnet-docs-samples,GoogleCloudPlatform/dotnet-docs-samples,GoogleCloudPlatform/dotnet-docs-samples,GoogleCloudPlatform/dotnet-docs-samples