Fix for Scheduler using build parameter from previous build

[dfederm]

This is a minor bug fix which ensures the Scheduler always uses the latest value for BuildParameters.DisableInProcNode rather than the value provided in the first build.

Note that the Scheduler is an IBuildComponent which has the same lifetime as the BuildManager. However, BuildParameters is per build, so caching a value from BuildParameters would be incorrect.

[Forgind]

The test failures are a known flaky thing at this point. I told them to rerun; hopefully they pass this time.