Add PictureInPictureParams#isSameAspectRatio [1/N]

This is to replace the float number check when comparing the given Rect
over aspect ratio. In this new static method, we allow for rounding
errors on width / height.

CTS tests have been updated to use and test this method.

What's next:
- Move the aspect ratio check from WMShell to Activity

Flag: EXEMPT refactor
Bug: 352118806
Test: atest CtsWindowManagerDeviceOther:PictureInPictureParamsTest
Change-Id: I205abb2b6cf4414be9ad8700ed1adf7fcea50ad5