[Jetpack Focus] Reenable Jetpack Notifications Disabling Feature Flag and Release Notes (#19761)

* Update RELEASE-NOTES.txt

* Reenable usage of remote feature flags

* Reenable local feature flag

Author: staskus

RELEASE-NOTES.txt

@@ -4,6 +4,7 @@
 * [***] [Jetpack-only] Adds a smooth, opt-in transition to the Jetpack app for users migrating from the WordPress app. [#19759]
 * [***] You can now migrate your site content to the Jetpack app without a hitch. [#19759]
 * [**] [internal] Upgrade React Native from 0.66.2 to 0.69.4 [https://github.com/wordpress-mobile/gutenberg-mobile/pull/5193]
+* [*] [internal] When a user migrates to the Jetpack app and allows notifications, WordPress app notifications are disabled. [#19616, #19611, #19590]
 
 21.3
 -----

WordPress/Classes/Services/JetpackNotificationMigrationService.swift

@@ -22,7 +22,7 @@ final class JetpackNotificationMigrationService: JetpackNotificationMigrationSer
     private let jetpackNotificationMigrationDefaultsKey = "jetpackNotificationMigrationDefaultsKey"
 
     private var jetpackMigrationPreventDuplicateNotifications: Bool {
-        return FeatureFlag.jetpackMigrationPreventDuplicateNotifications.enabled
+        return featureFlagStore.value(for: FeatureFlag.jetpackMigrationPreventDuplicateNotifications)
     }
 
     private var notificationSettingsService: NotificationSettingsService?