Fix .metadata.annotations.alm-examples

[eguzki]

OperatorHub takes only the first example for a given CRD as example when trying to deploy a CR for that CRD from the dashboard.

Currently the repo includes multiple APIManager CR examples, but only one is required.

To be done: Only one CR per CRD in .metadata.annotations.alm-examples.

Put all the (remaining) samples in doc/samples for the validation tasks. The tests from github.com/3scale/3scale-operator/test/crds need to be updated