CR: Add translation comment

// FREEBIE

Signal/src/ViewControllers/NotificationSettingsViewController.m

@@ -53,7 +53,11 @@
                                    OWSSoundSettingsViewController *vc = [OWSSoundSettingsViewController new];
                                    [weakSelf.navigationController pushViewController:vc animated:YES];
                                }]];
-    [soundsSection addItem:[OWSTableItem switchItemWithText:NSLocalizedString(@"NOTIFICATIONS_SECTION_INAPP", nil)
+
+    NSString *inAppSoundsLabelText = NSLocalizedString(@"NOTIFICATIONS_SECTION_INAPP",
+        @"Table cell switch label. When disabled, Signal will not play notification sounds while the app is in the "
+        @"foreground.");
+    [soundsSection addItem:[OWSTableItem switchItemWithText:inAppSoundsLabelText
                                                        isOn:[prefs soundInForeground]
                                                      target:weakSelf
                                                    selector:@selector(didToggleSoundNotificationsSwitch:)]];

Signal/translations/en.lproj/Localizable.strings

@@ -1149,7 +1149,7 @@
 /* No comment provided by engineer. */
 "NOTIFICATIONS_NONE" = "No Name or Content";
 
-/* No comment provided by engineer. */
+/* Table cell switch label. When disabled, Signal will not play notification sounds while the app is in the foreground. */
 "NOTIFICATIONS_SECTION_INAPP" = "Play While App is Open";
 
 /* Label for settings UI that allows user to change the notification sound. */