Resolve conflicts for functions introduced in Android API level 35.
* lib/time.in.h (timespec_getres): Consider REPLACE_TIMESPEC_GETRES.
* m4/time_h.m4 (gl_TIME_H_DEFAULTS): Initialize REPLACE_TIMESPEC_GETRES.
* modules/time-h (Makefile.am): Substitute REPLACE_TIMESPEC_GETRES.
* m4/timespec_getres.m4 (gl_FUNC_TIMESPEC_GETRES): Test for
timespec_getres using gl_CHECK_FUNCS_ANDROID instead of
AC_CHECK_FUNCS_ONCE. Conditionally set REPLACE_TIMESPEC_GETRES.
* modules/timespec_getres (Depends-on, configure.ac): Consider
REPLACE_TIMESPEC_GETRES.
* m4/gettime.m4 (gl_GETTIME_RES): Test for timespec_getres using
gl_CHECK_FUNCS_ANDROID instead of AC_CHECK_FUNCS_ONCE.
* doc/posix-functions/timespec_getres.texi: Mention the Android API
levels.