getCameraForGeometry returns very wrong values when map is tilted

[westnordost]

Describe the bug
getCameraForGeometry(Geometry geometry, int[] padding) should return the necessary camera zoom and position to enclose the given geometry on the current camera rotation and tilt.

This works fine for any rotation, but with tilt, this sometimes calculates a zoom much much lower than would be appropriate. The decisive factor for how wrong the calculation turns out to be seems to be the current camera position in relation to the position of the geometry. See the video:

Tilt.Zoom.Out.mp4

To Reproduce
Reproducable with https://github.com/streetcomplete/StreetComplete/releases/tag/v59.0-alpha2

A minimum test with which this should be reproducible is to have a GeoJson layer with one geometry that focuses the camera on tap without changing rotation or tilt. Then, tilt the map and select it like in the video.

Expected behavior
Correct calculation for getCameraForGeometry

Platform information:

• Android, any version
• Version 11.2.0

Additional context
Originally reported in streetcomplete/StreetComplete#5858

This is likely related to #2255, as surely the same algorithm is used to convert a lat-lon-pair to screen coordinates and back.