test(@angular-devkit/core): add missing parameter in angular-workspace.json

[nweldev]

In a6767dc, a defaultProject was added to workspaceJson in workspace_spec, which hasn't been
synced with tests/@angular_devkit/workspace/angular-workspace.json as expected. This was breaking
the related tests with more than one project, like in #739.

[nweldev]

My bad, I missed all the customWorkspaceJson behaviours, so I fixed my tests in #789 better following the ones in a6767dc and this doesn't seems to be relevant anymore.

But I still would have a question about this (poke @filipesilva): is the comment about keeping the workspaceJson in sync with the json file still relevant if we can override it when we need ? If so, why ?

Keeping this PR open in order to discuss this and do the according updates.

[filipesilva]

@noelmace I don't follow, what comment are you referring to?

[nweldev]

@filipesilva Oh sorry about that. This one : https://github.com/angular/devkit/blob/master/packages/angular_devkit/core/src/workspace/workspace_spec.ts#L24

[filipesilva]

It should be kept in sync so another test (the one that tests the schema itself) is testing the same thing.

[nweldev]

Thanks a lot for your response. Let me know if you think I should change this json file in #872 then.