seccomp: add arm_fadvise64_64 to system-service group

fadvise64 and fadvise64_64 are already in the group, but arm_ version
was not.

Fixes #28350.

src/shared/seccomp-util.c

@@ -890,6 +890,7 @@ const SyscallFilterSet syscall_filter_sets[_SYSCALL_FILTER_SET_MAX] = {
                 "@signal\0"
                 "@sync\0"
                 "@timer\0"
+                "arm_fadvise64_64\0"
                 "capget\0"
                 "capset\0"
                 "copy_file_range\0"