My phone just went through the lollipop upgrade (5.0.2) yesterday. All of a sudden, when a text comes in, my camera flash activates. Where do I turn this off? I have looked and looked and can't seem to find it. FYI.....Not the best software upgrade!
This setting shouldn't have changed, and you will need to do a complete factory reset disabling App Backup and Restore, but for the time being:
Settings---Accessibility---Scroll down to Flash Alerts.
The following process has helped many, maybe you can benefit from this as well. I know you don't WANT to FDR, but if you haven't already, this might be a NEED to operation.
Back up any photos documents or videos and other media to a PC or cloud service. Google Accounts will keep your contacts in Gmail and you can use Google Drive to back up everything instead of a PC and the Play Store will remember the apps you have downloaded before.
Plug into charger for the entire process
(DISABLE google backup and restore of apps and app data)
Charge to 100% and back up and factory reset the phone
Factory reset one more time
Unplug from charger
Set up your phone
Leave phone on until it dies and turns off 1 time
Leave off and recharge to 100%
This is my usual process and I have had no issues.