I have upgraded my Alcatel Flash 2 to 3.8 last month. And I have noticed something that the front camera switch is missing. I found it just now when I was about to take a selfie in a convention.
The only way to have it back is to Restore the default setting of the camera. Kindly check. I think this is a bug in an update.
Just clear cache and data from Settings>Apps>All>Camera
Nope. Not there. Not working.
Only way to have it back is
Camera > Return to Default Settings only to find that it's gone again.