AndroidBackend: API 30 compatibility

[bbrk24]

This PR updates the helpers so that AndroidBackendHelpers doesn't use any functionality introduced in API 34, partially resolving #579. It still requires API 30 and crashes instantly on API 28 or 29. I also didn't touch the AlertFragment since I already did that in #581.

[MiaKoring]

The most important part: Works!

Thank you, thats really helpful. I will give onHover a shot again once this is merged

[MiaKoring]

The code changes look logical too. Basically same logic, but different source for density and basically polyfilling the one function for older versions.

Only question I have: Is there a benefit to using the function on the newer API version instead of the division / do we know what the function does internally? if the function just does a division too, it might be nicer to use it for both. Otherwise, if the function is cheaper it undoubtedly makes sense to do it like that

[bbrk24]

Yes, starting with API 34 the relationship between SP and PX is no longer guaranteed to be linear, so a simple division is not necessarily correct.

[MiaKoring]

lgtm

[stackotter]

Thanks for resolving these compatibility issues 🙏