CloudMemorystore does not test UpToDate logic in ExternalObservation

[hasheddan]

What problem are you facing?

As of https://github.com/crossplaneio/crossplane-runtime/commit/ab3cac0175cece1866404a2e1d2d514f65a81fee the Observe() method reports back whether a external resource needs to be updated or not. Therefore, the IsUpToDate logic is being checked in Observe() rather than Update(). When CloudMemorystore was moved to v1beta1, it started using this pattern, but it does not test the value of ResourceUpToDate in the ExternalObservation in TestObserve.

How could Crossplane help solve your problem?

TestObserve should be updated to test that we report resource needs update when IsUpToDate returns false.