protected Set<String> getRequiredApps() {
        HashSet<String> requiredApps = new HashSet<String>();
        requiredApps.addAll(mRequiredAppsList);
        requiredApps.addAll(mVendorRequiredAppsList);
        requiredApps.add(mMdmPackageName);
        return requiredApps;
    }
Returns if this task should be run on OTA.
This is indicated by the presence of the system apps file.
engine/src/main/java/com/oasisfeng/island/provisioning/task/DeleteNonRequiredAppsTask.java