Make the edit activity fullscreen

Currently, the gesture bar is visible at the bottom of the activity.
This change hides all system bars to make the activity fullscreen.

Fixes: 318844779
Test: flashed device and verified edit activity is fullscreen
Flag: ACONFIG com.android.systemui.communal_hub DEVELOPMENT
Change-Id: Ia2c3339f6c11c45b119aef004461fe5dcbe2b193