Bug 1796348 - Add a notification delegate to MediaSessionService.

The MediaSessionService will now show notifications through the notification delegate.
MediaSessionService will also use the notificationManager from the notification delegate.

app/src/main/java/org/mozilla/fenix/media/MediaSessionService.kt

@@ -7,6 +7,7 @@ package org.mozilla.fenix.media
 import mozilla.components.browser.state.store.BrowserStore
 import mozilla.components.concept.base.crash.CrashReporting
 import mozilla.components.feature.media.service.AbstractMediaSessionService
+import mozilla.components.support.base.android.NotificationsDelegate
 import org.mozilla.fenix.ext.components
 
 /**
@@ -15,4 +16,5 @@ import org.mozilla.fenix.ext.components
 class MediaSessionService : AbstractMediaSessionService() {
     override val store: BrowserStore by lazy { components.core.store }
     override val crashReporter: CrashReporting by lazy { components.analytics.crashReporter }
+    override val notificationsDelegate: NotificationsDelegate by lazy { components.notificationsDelegate }
 }