Bug 1750989 - Add Shaw to the TRR telemetry keys r=necko-reviewers,kershaw

Differential Revision: https://phabricator.services.mozilla.com/D136378

netwerk/dns/TRRService.cpp

@@ -49,6 +49,7 @@ constexpr nsLiteralCString kTRRDomains[] = {
     "firefox.dns.nextdns.io"_ns,
     "private.canadianshield.cira.ca"_ns,
     "doh.xfinity.com"_ns,  // Steered clients
+    "dns.shaw.ca"_ns, // Steered clients
     // clang-format on
 };