Fixes bug where the camera app would launch below the lock-screen

In ag/19119857, we accidentally removed the logic that would dismiss the non-secure
"swipe" screen lock when the camera app would be launched by a
double-tap on the power button. This CL fixes that.

Test: manually verified the following:
1. With Screen Lock set to an insecure "Swipe", when the screen is locked,
   double-tapping the power button opens the camera app *on top of the
   lock-screen*. Hitting the back button when the camera app is in the
   foreground returns to the **unlocked** home screen
2. With Screen Lock set to a secure "Pattern", when the screen is locked,
   double-tapping the power button opens the camera app *on top of the
   lock-screen*. Hitting the back button when the camera app is in the
   foreground returns to the locked lock-screen
3. When unlocked and on the home screen, double-tapping the power button
   brings the camera app to the foreground. Hitting the back button
   returns to the home screen
Bug: b/235403546, b/238277981

Change-Id: I39b7c8ce2b93d9e95c89ab5625870e6263f77b70