@TargetApi(Build.VERSION_CODES.KITKAT)
    private static boolean isLowMemoryDevice(ActivityManager activityManager) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            return activityManager.isLowRamDevice();
        } else {
            return Build.VERSION.SDK_INT < Build.VERSION_CODES.HONEYCOMB;
        }
    }
Returns the recommended bitmap pool size for the device it is run on in bytes.
core/src/main/java/com/bumptech/glide/load/engine/cache/MemorySizeCalculator.java