Bug 1550139 - Add a subcategory for linking directly to the Logins & Passwords preferences. r=MattN

I'll add the menuitem in about:logins in bug 1550135.

Differential Revision: https://phabricator.services.mozilla.com/D34025

--HG--
extra : moz-landing-system : lando

browser/components/preferences/in-content/privacy.xul

@@ -418,7 +418,7 @@
 </groupbox>
 
 <!-- Passwords -->
-<groupbox id="passwordsGroup" orient="vertical" data-category="panePrivacy" hidden="true">
+<groupbox id="passwordsGroup" orient="vertical" data-category="panePrivacy" data-subcategory="logins" hidden="true">
   <label><html:h2 data-l10n-id="logins-header"/></label>
 
   <vbox id="passwordSettings">

browser/components/preferences/in-content/tests/browser_spotlight.js

@@ -8,6 +8,8 @@ add_task(async function test_openPreferences_spotlight() {
      "panePrivacy", "#privacy", "credit-card-autofill"],
     ["privacy-form-autofill",
      "panePrivacy", "#privacy", "form-autofill"],
+    ["privacy-logins",
+     "panePrivacy", "#privacy", "logins"],
     ["privacy-trackingprotection",
      "panePrivacy", "#privacy", "trackingprotection"],
     ["privacy-permissions-block-popups",