Bug 1639504 - Update ETP card content summary. r=ewright,fluent-reviewers,flod

Differential Revision: https://phabricator.services.mozilla.com/D76112

browser/components/protections/content/protections.html

@@ -35,7 +35,7 @@
           <div class="wrapper">
             <div>
               <h2 class="card-title" data-l10n-id="etp-card-title-always"></h2>
-              <p id="etp-card-content" class="content" data-l10n-id="etp-card-content-summary"></p>
+              <p id="etp-card-content" class="content" data-l10n-id="etp-card-content-description"></p>
             </div>
             <a target="_blank" id="manage-protections" data-l10n-id="protection-report-manage-protections"></a>
           </div>

browser/locales/en-US/browser/protections.ftl

@@ -32,7 +32,7 @@ protection-report-settings-link = Manage your privacy and security settings
 
 etp-card-title-always = Enhanced Tracking Protection: Always On
 etp-card-title-custom-not-blocking = Enhanced Tracking Protection: OFF
-etp-card-content-summary = When unknown companies try to secretly follow you around the web, { -brand-short-name } automatically stops many of them.
+etp-card-content-description = { -brand-short-name } automatically stops companies from secretly following you around the web.
 protection-report-etp-card-content-custom-not-blocking = All protections are currently turned off. Choose which trackers to block by managing your { -brand-short-name } protections settings.
 protection-report-manage-protections = Manage Settings