Overhaul activity checking to be cleaner

[judemanutd]

Original Issue : #27

refrain from catching an exception while trying to open an activity and falling back to a different one then. The "cleaner" alternative would be to check which one of the activities is actually present beforehand, without having to trigger an exception. But this really shouldn't affect the UX, so it doesn't really matter that much. Though the current fallback will very soon become the primary activity, as Huawei devices get updated.

Helper Issue : #29

Code snippet that should help

        Intent intent = new Intent();
        intent.setComponent(new ComponentName(packageName, componentName));
        if (intent.resolveActivity(context.getPackageManager()) != null) {
            // the intent is exist
        }