seccomp: add mseal to seccomp policy (tlsdate)

mseal might be called when process call dlopen() and
mmap new dll.

Add mseal to seccomp policies which have mmap.

BUG=b:373509070
TEST=CQ

Change-Id: I3300f96ec078bb1b84782deaedc726412d660560
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/tlsdate/+/5986002
Reviewed-by: Allen Webb <allenwebb@google.com>
Reviewed-by: Hugo Benichi <hugobenichi@google.com>
Commit-Queue: Jeff Xu <jeffxu@google.com>
Auto-Submit: Jeff Xu <jeffxu@google.com>
Tested-by: Jeff Xu <jeffxu@google.com>
4 files changed