Modify buildpacks sample build strategy to use updated pattern from Tekton catalog

[SaschaSchwarze0]

In our build strategy for Buildpacks we have one step for each lifecycle phase of Buildpacks (detect, restore, build, export). There was an update to the Tekton catalog in Rename Buildpacks-V3 task to Buildpacks, and add Buildpacks-Phases task #415 which changes to the creator binary which combines all these phases. We should apply this to our build strategy samples to simplify them.

Must have is updating those for Paketo: buildstrategy_buildpacks-v3_cr.yaml / buildstrategy_buildpacks-v3_namespaced_cr.yaml. I do not know if Heroku supports the same as well, is worth trying.