gralloc: move VtsHalCameraProviderV2_4TargetTest to GraphicBufferAllocator/Mapper

libui's GraphicBufferAllocator/Mapper already wrap the different
gralloc functions and hide the details from the caller. There is no
reason VtsHalCameraProviderV2_4TargetTest needs to directly talk to
gralloc. This patch updates VtsHalCameraProviderV2_4TargetTest to
use libui.

Bug: 145139476
Test: adb shell /system/bin/VtsHalCameraProviderV2_4TargetTest
--hal_service_instance=android.hardware.camera.provider@2.4::ICameraProvider/internal/0

Change-Id: I2c2a913f6c5aea2ce7260b68293df404f40e0ddd