[GWP-ASan] Change sys/cdefs.h to features.h

sys/cdefs.h is a glibc internal header which is not supposed to be included by applications.
(Some libc implementations provide this file for compatibility.)
Android features.h includes sys/cdefs.h, so we can include features.h instead.

This change makes `ninja gwp_asan` build on musl.

GitOrigin-RevId: da59c2e4dc1c7b502cc2098247b2ee38ac297e0c
1 file changed