<local name="SUPPORT_NIGHT_MODE_ZOOM" value="true"/>
Add these lines to /system/system/cameradata/camera-feature.xml and reboot. Wipe the camera app's data and you'll have night mode working on front cam and telephoto lens in S9/S9+/N9 on One UI 2.
The front camera quality improves significantly in night mode.
Join t.me/ZexynosLounge for a stable GCam6.1 and more camera mods
Tested on S9+ running One UI 2 beta ZTA2 build