Disable 3-Button NavBar Recents key when launch secure camera

In general, recents key is useless in double click power key launch
camera CUJ, we can hide recents to prevent user click and invoke
Keyguard face auth while the camera is running concurrently.

And at the moment, face auth is not able to access camera, then
fallback to fingerprint authentication.

While user see dim beyond camera preview, and face auth not work
bring bad UX to user, disable Recent key in the scenario sounds
make sense.

Bug: 268593702
Test: Double click to launch camera in 3-button Nav mode
      make sure recent key is hide
Test: atest KeyguardViewMediatorTest
Change-Id: I5cc50b8bb49725f6e53445bdd1c9e3a8d0a15a88