Update interstitials to match the new security indicators
I've gated this change using the Feature API, behind the feature name
SecurityWarningIconUpdate. That way we can monitor the CTR impact and
roll back if necessary.
Squashed pngs using tools/resources/optimize-png-files.sh -o2.
Screenshots on the bug.
BUG=
629140
Committed:
https://crrev.com/bd00bd10a193ca94ba6145cdba65f4e3f0a2cc6a
Cr-Commit-Position: refs/heads/master@{#406183}