[cr105 follow up] Fixes favicon in Shields Panel.

Fixes brave/brave-browser#24954

The chrome://favicon2 syntax has changed to camelCase.

Chromium change:

https://source.chromium.org/chromium/chromium/src/+/78e45e119c9aca1eabf7e0b23764d1923f25a720

commit 78e45e119c9aca1eabf7e0b23764d1923f25a720
Author: Solomon Kinard <solomonkinard@chromium.org>
Date:   Mon Jun 13 23:45:53 2022 +0000

    Favicon: Use camelCase params instead of snake_case in JS context

    Doc:
    https://docs.google.com/document/d/1ksvSq1zF-9jYSfGOvNluyoTV0Ud9xl6r9HiAKONqmz8

    Context: crrev.com/c/3673461

    Bug: 104102

browser/ui/brave_shields_data_controller.cc

@@ -163,9 +163,9 @@ GURL BraveShieldsDataController::GetCurrentSiteURL() {
 GURL BraveShieldsDataController::GetFaviconURL(bool refresh) {
   auto url = GURL("chrome://favicon2/");
   url = AppendQueryParameter(url, "size", "16");
-  url = AppendQueryParameter(url, "scale_factor", "2x");
-  url = AppendQueryParameter(url, "show_fallback_monogram", "");
-  url = AppendQueryParameter(url, "page_url",
+  url = AppendQueryParameter(url, "scaleFactor", "2x");
+  url = AppendQueryParameter(url, "showFallbackMonogram", "");
+  url = AppendQueryParameter(url, "pageUrl",
                              GetCurrentSiteURL().GetWithoutFilename().spec());
 
   if (refresh) {