Add slot machine animation for PredictedAppIcon

PredictedAppIcon has the ability to create a "slot machine" animation which cycles through given icons and settles back on the original icon.

Currently the animation isn't used, but here's how you could start it:
if (view instanceof PredictedAppIcon) {
    List<BitmapInfo> randomIcons =
            mLauncher.getAppsView().getAppsStore().getApps()
            .stream()
            .map(appInfo -> appInfo.bitmap)
            .sorted(Utilities.getRandomComparator())
            .limit(3)
            .collect(Collectors.toList());
    ((PredictedAppIcon) view).createSlotMachineAnim(randomIcons)
            .setDuration(1000).start();
}

Test: Played the animation locally
Bug: 180605356
Change-Id: I43bfbc41256fb99ee9df3732fd493e6b96bde7cb