enable SSL certificate pinning for important Brave domains

[diracdeltas]

Test plan

See #12190 (comment)

Original issue description

we should mitigate against TLS MITM attacks by using certificate pinning / expect-CT for important domains in browser-laptop (Brave update server, Brave extensions update server, ledger servers, etc.). this may be doable by simply adding to https://chromium.googlesource.com/chromium/src/net/+/master/http/transport_security_state_static.json

cc @jumde

[diracdeltas]

This was done in brave/muon#401

[diracdeltas]

Test plan:

1. remove the browser profile folder
2. open devtools and go to http://roundcube.mayfirst.org
3. in the network requests devtools tab, you should see http://roundcube.mayfirst.org redirect to https with a 307 code

[LaurenWags]

Works on MacOS:

[kjozwiak]

Same results as @LaurenWags under Win 10 x64 and Ubuntu 17.10 x64 using 0.19.13838f8509.