Ensure checkbox is hidden when feature is not enabled

As a follow-up to
https://chromium-review.googlesource.com/c/chromium/src/+/1930820
this CL ensure that the "Inform quietly" checkbox is not visible if
the `QuietNotificationPrompts` feature is disabled.

Bug: 1014874
Change-Id: I205d46c86c1714f06e62849a10b1348252631930
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1946484Reviewed-by: Kamila Hasanbega <hkamila@chromium.org>
Commit-Queue: Andy Paicu <andypaicu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#720877}

chrome/android/java/src/org/chromium/chrome/browser/settings/website/SingleCategoryPreferences.java

@@ -887,7 +887,12 @@ public class SingleCategoryPreferences extends PreferenceFragmentCompat
                 screen.removePreference(notificationsVibrate);
             }
 
-            notificationsQuietUi.setOnPreferenceChangeListener(this);
+            if (ChromeFeatureList.isEnabled(ChromeFeatureList.QUIET_NOTIFICATION_PROMPTS)) {
+                notificationsQuietUi.setOnPreferenceChangeListener(this);
+            } else {
+                screen.removePreference(notificationsQuietUi);
+            }
+
             updateNotificationsSecondaryControls();
         } else {
             screen.removePreference(notificationsVibrate);
@@ -1008,6 +1013,8 @@ public class SingleCategoryPreferences extends PreferenceFragmentCompat
                         NOTIFICATIONS_VIBRATE_TOGGLE_KEY);
         if (vibrate_pref != null) vibrate_pref.setEnabled(categoryEnabled);
 
+        if (!ChromeFeatureList.isEnabled(ChromeFeatureList.QUIET_NOTIFICATION_PROMPTS)) return;
+
         // The notifications quiet ui checkbox.
         ChromeBaseCheckBoxPreference quiet_ui_pref =
                 (ChromeBaseCheckBoxPreference) getPreferenceScreen().findPreference(

chrome/android/javatests/src/org/chromium/chrome/browser/settings/website/SiteSettingsPreferencesTest.java

@@ -36,6 +36,7 @@ import org.chromium.chrome.browser.settings.SettingsActivity;
 import org.chromium.chrome.test.ChromeActivityTestRule;
 import org.chromium.chrome.test.ChromeJUnit4ClassRunner;
 import org.chromium.chrome.test.util.InfoBarTestAnimationListener;
+import org.chromium.chrome.test.util.browser.Features.EnableFeatures;
 import org.chromium.chrome.test.util.browser.LocationSettingsTestUtil;
 import org.chromium.content_public.browser.test.util.TestThreadUtils;
 import org.chromium.content_public.common.ContentSwitches;
@@ -449,6 +450,7 @@ public class SiteSettingsPreferencesTest {
     @Test
     @SmallTest
     @Feature({"Preferences"})
+    @EnableFeatures("QuietNotificationPrompts")
     public void testOnlyExpectedPreferencesShown() {
         // If you add a category in the SiteSettings UI, please add a test for it below.
         Assert.assertEquals(19, SiteSettingsCategory.Type.NUM_ENTRIES);