[nearby][clean up] Remove HalfSheetUX from apex

Dead code clean up

Test: -m
Bug: 292812342
Bug: 297413048
Merged-In: I7efa92469f0c061a972a7dadf6a38686b78c61b4
Change-Id: Icc2f1f206cfab99694f68a60082d4743d739cfe9
1 file changed