build: only test for broken ip_mreq_source on Android. Fixes #1472

7efd76dd added these configure time tests to work around a bug with older Android. Since the test didn't take Windows into account it wrongfully applied the workaround on Windows too, breaking the build. With meson this wasn't an issue since the check is skipped on Windows there and our CI didn't catch this issue.

Change the test to run on Android only for meson and autotools. This also makes it clear that the test+code can be dropped again if we stop supporting older Android versions at some point.