P: Spawn WB picker in the center of screen instead of center of image

When you summon the white balance selector tool (dropper icon) on mobile, it will spawn in the center of the image, regardless of where you're zoomed into on the image. You may for example zoom into a corner of the image which contains the WB sample you wish to use, but upon clicking the dropper icon, the tool will spawn off screen and you will not be able to select your WB sample. This would be better if the tool spawned in the center of the screen, instead of the center of the image.