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 <[email protected]>
Reviewed-by: Hugo Benichi <[email protected]>
Commit-Queue: Jeff Xu <[email protected]>
Auto-Submit: Jeff Xu <[email protected]>
Tested-by: Jeff Xu <[email protected]>
4 files changed