Add aconfig for Biometrics

Creates aconfig for biometrics in com.android.systemui.shared – allows
for flagging cross-process changes across SysUI and system_server

Bug: 315392880
Flag: ACONFIG com.android.systemui.shared.sidefps_controller_refactor DEVELOPMENT
Test: n/a
Change-Id: Ia23dddd5b6b3c35351b18e6f800f0a07aa6397cf
1 file changed