Use slightly less memory by not building as part of the test step.
Use slightly less memory by not building as part of the test step.

Change-Id: I99c405aa64073cf075bb03b2b8c3849c591bd849

GoogleCloudPlatform/dotnet-docs-samples,GoogleCloudPlatform/dotnet-docs-samples,jsimonweb/csharp-docs-samples,jsimonweb/csharp-docs-samples,jsimonweb/csharp-docs-samples,GoogleCloudPlatform/dotnet-docs-samples,GoogleCloudPlatform/dotnet-docs-samples,jsimonweb/csharp-docs-samples