The Android L Developer's Preview is just that, a "Preview" for developers to work with. If you flashed a "snapshot" I guess you are referring to that. You made a backup of your ROM prior to flashing the preview I hope? You can flash that back and use the Android L dump download to add Android L apps for now, or go to Developers.google.com and download the latest factory image for your device. I am going to wait until they release the next version as there are enough bugs and security issues to deal with as it is. Good Luck, either way...