Pin test page for TLS pinning

[fmarier]

Now that we have a test page which is using a CA outside of our pinset (Sectigo), we need to pin it in order to trigger the interstitial page.

[stephendonner]

Verified PASSED using

Brave	1.32.31 Chromium: 94.0.4606.61 (Official Build) nightly (x86_64)
Revision	418b78f5838ed0b1c69bb4e51ea0252171854915-refs/branch-heads/4606@{#1204}
OS	macOS Version 11.6 (Build 20G165)

Steps:

1. clean profile
2. launched Brave
3. loaded https://ssl-pinning.someblog.org/

Confirmed I now see the interstitial warning page

before	after

---

Verification passed on

Brave | 1.32.78 Chromium: 95.0.4638.54 (Official Build) beta (64-bit)
-- | --
Revision | d31a821ec901f68d0d34ccdbaea45b4c86ce543e-refs/branch-heads/4638@{#871}
OS | Windows 10 Version 21H1 (Build 19043.1288)

Confirmed I now see the interstitial warning page after navigating to https://ssl-pinning.someblog.org/

before	after

---

Verified PASSED using

Brave	1.32.78 Chromium: 95.0.4638.54 (Official Build) beta (64-bit)
Revision	d31a821ec901f68d0d34ccdbaea45b4c86ce543e-refs/branch-heads/4638@{#871}
OS	Linux

Steps:

1. new profile
2. launch Brave
3. loaded https://ssl-pinning.someblog.org in both current release and 1.32.x

before	after