Certificate Transparency: Add Symantec's log

Symantec's log has been monitored for the required period and was
found compliant.

BUG=483625

Review URL: https://codereview.chromium.org/1287063007

(cherry picked from commit 9563016b34d5518b1fb14c903170606797c3db26)

Cr-Original-Commit-Position: refs/heads/master@{#343873}
Cr-Commit-Position: refs/branch-heads/2454@{#407}
Cr-Branched-From: 12bfc3360892ec53cd00fc239a47e5298beb063b-refs/heads/master@{#338390}
1 file changed