Move Android OS check to the __ANDROID__ macro
Hi all,
As requested in !6477 (comment 2349239) (source: https://gitlab.gnome.org/GNOME/glib/-/merge_requests/3987#note_2068881), this PR moves all the Android, non-Bionic specific checks to use the __ANDROID__
preprocessor definition. I followed the guidance in this Google document: https://android.googlesource.com/platform/bionic/+/HEAD/docs/defines.md
See https://gitlab.gnome.org/GNOME/glib/-/merge_requests/3993