random: Fix compilation error on Android 4.3. * lib/stdlib.in.h (random, srandom): Test also REPLACE_RANDOM. (initstate): Test REPLACE_INITSTATE and HAVE_INITSTATE, not HAVE_RANDOM. (setstate): Test REPLACE_SETSTATE and HAVE_SETSTATE, not HAVE_RANDOM. * m4/random.m4 (gl_FUNC_RANDOM): Set HAVE_INITSTATE, HAVE_SETSTATE, REPLACE_RANDOM, REPLACE_INITSTATE, REPLACE_SETSTATE. * m4/stdlib_h.m4 (gl_STDLIB_H_DEFAULTS): Initialize HAVE_INITSTATE, HAVE_SETSTATE, REPLACE_RANDOM, REPLACE_INITSTATE, REPLACE_SETSTATE. * modules/stdlib (Makefile.am): Substitute HAVE_INITSTATE, HAVE_SETSTATE, REPLACE_RANDOM, REPLACE_INITSTATE, REPLACE_SETSTATE. * modules/random (Depends-on, configure.ac): Test also REPLACE_RANDOM, REPLACE_INITSTATE, REPLACE_SETSTATE. * doc/posix-functions/random.texi: Correct the description of the situation on Android. * doc/posix-functions/srandom.texi: Likewise. * doc/posix-functions/rand.texi: Likewise. * doc/posix-functions/srand.texi: Likewise.