Fixes android symbol loader not having is_loaded (build error)

[lattice0]

Fixes #1307

• Tested on all platforms changed
• Compilation warnings were addressed
• cargo fmt has been run on this branch
• cargo doc builds successfully
• Added an entry to CHANGELOG.md if knowledge of this change could be valuable to users
• Updated documentation to reflect any user-facing changes, including notes of platform-specific behavior
• Created or updated an example program if it would help users understand this functionality

[lattice0]

Hello, before I fix the CI/CD stuff and the missing checkboxes, can I know if something's missing? I think these changes fix the problem. Android seems to not have dynamic loading of dynamically loadable libs so there's no .is_loaded() for it.

[lattice0]

PS: all testes failed because I pointed to a local winit for my stuff. Gonna fix it soon but currently maybe leave like this so my local project works, is there a problem? just want to keep things simple

[MarijnS95]

FYI this is going to get closed when #1398 is merged, which turns out to be a better solution to this problem.