[WebLayer] Hide 'Learn more' link on 'Protected content' site settings page

Bug: 1085553
Change-Id: I899f426dcde936b2c8d4443e657f7a6378576477
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2261699Reviewed-by: Finnur Thorarinsson <finnur@chromium.org>
Commit-Queue: Robbie McElrath <rmcelrath@chromium.org>
Cr-Commit-Position: refs/heads/master@{#781982}

components/browser_ui/site_settings/android/java/src/org/chromium/components/browser_ui/site_settings/SingleCategorySettings.java

@@ -1023,7 +1023,8 @@ public class SingleCategorySettings extends SiteSettingsPreferenceFragment
         }
 
         // Only show the link that explains protected content settings when needed.
-        if (mCategory.showSites(SiteSettingsCategory.Type.PROTECTED_MEDIA)) {
+        if (mCategory.showSites(SiteSettingsCategory.Type.PROTECTED_MEDIA)
+                && getSiteSettingsClient().getSiteSettingsHelpClient().isHelpAndFeedbackEnabled()) {
             explainProtectedMediaKey.setOnPreferenceClickListener(preference -> {
                 getSiteSettingsClient()
                         .getSiteSettingsHelpClient()