ParceledListSlice<ApplicationInfo> getInstalledApplications(final int flags, final int user) throws RemoteException {
            return () -> mPackageManager.getInstalledApplications(flags);
        }
Runs the next task when all packages have been deleted or shuts down the activity if package
deletion fails.
engine/src/main/java/com/oasisfeng/island/provisioning/task/DeleteNonRequiredAppsTask.java