fw/workload: Don't override the package manager for ApkRevent workloads
fw/workload: Don't override the package manager for ApkRevent workloads

`ApkRevent` workloads should be able to use the same Apk selection
criteria as `ApkWorkloads` therefore rely on the superclass to
instantiate the `PackageHandler`.

ARM-software/workload-automation,ARM-software/workload-automation,ARM-software/workload-automation,setrofim/workload-automation,setrofim/workload-automation,setrofim/workload-automation,ARM-software/workload-automation,setrofim/workload-automation