I just purchased a few refurbished Samsung (S3, S4, S5) devices from Gazelle for a testing lab I'm organizing. The product listings for each said they had Android 4.2, 4.3, and 4.4 respectively. However, when they arrived and booted up, they all appear to have 4.4.2 installed. Factory reset seems to only reset to version 4.4.2. Is there a way to (without rooting) revert the devices back to previous versions of Android?