Merge "Update printers even if there are no printers found." into nyc-dev

        // The contract is that if we already have a valid,

        // result the we have to deliver it immediately.

        if (!mPrinters.isEmpty()) {

        (new Handler(Looper.getMainLooper())).post(new Runnable() {

            @Override public void run() {

                deliverResult(new ArrayList<>(mPrinters));

            }

        });

        // Always load the data to ensure discovery period is

        // started and to make sure obsolete printers are updated.

        onForceLoad();