Snapshots on iOS 16 sometimes show activation point unexpectedly

[Nick Entin]

Adding iOS 16 to our project's test config yielded many new crosshair overlays on buttons. There may be a pixel-rounding change that AccessibilityHierarchyParser.defaultActivationPoint(for: ) needs to take into account. And on that note, that method could be sensitive to text fields that are first responder (where the activation point is on the insertion bar rather than the center of the view).

Originally posted by @pwesten in #117 (comment)

[Nick Entin]

Reproduced this on iOS 17. Looks like it's sub-pixel offsets.

(lldb) po activationPoint
▿ (173.0, 425.83333333333337)
  - x : 173.0
  - y : 425.83333333333337
(lldb) po defaultActivationPoint(for: element.object)
▿ (172.91666666666666, 426.0)
  - x : 172.91666666666666
  - y : 426.0