For #7996: Private mode doesn't play nicely with sites added to home screen

Site Controls Notification should reflect the browsing mode of the
currernt web app session.

app/src/main/java/org/mozilla/fenix/customtabs/ExternalAppBrowserFragment.kt

@@ -73,7 +73,7 @@ class ExternalAppBrowserFragment : BaseBrowserFragment(), UserInteractionHandler
                         activity = activity,
                         engineLayout = view.swipeRefresh,
                         onItemTapped = { browserInteractor.onBrowserToolbarMenuItemTapped(it) },
-                        isPrivate = (activity as HomeActivity).browsingModeManager.mode.isPrivate,
+                        isPrivate = it.private,
                         shouldReverseItems = !activity.settings().shouldUseBottomToolbar
                     ),
                     owner = this,
@@ -135,7 +135,13 @@ class ExternalAppBrowserFragment : BaseBrowserFragment(), UserInteractionHandler
                             requireComponents.core.sessionManager,
                             requireComponents.useCases.sessionUseCases.reload,
                             customTabSessionId,
-                            manifest
+                            manifest,
+                            WebAppSiteControlsBuilder(
+                                requireComponents.core.sessionManager,
+                                requireComponents.useCases.sessionUseCases.reload,
+                                customTabSessionId,
+                                manifest
+                            )
                         )
                     )
                 } else {

app/src/main/java/org/mozilla/fenix/customtabs/WebAppSiteControlsBuilder.kt

@@ -0,0 +1,45 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.fenix.customtabs
+
+import android.content.Context
+import android.content.Intent
+import android.content.IntentFilter
+import androidx.core.app.NotificationCompat
+import mozilla.components.browser.session.Session
+import mozilla.components.browser.session.SessionManager
+import mozilla.components.concept.engine.manifest.WebAppManifest
+import mozilla.components.feature.pwa.feature.SiteControlsBuilder
+import mozilla.components.feature.session.SessionUseCases
+import org.mozilla.fenix.R
+
+class WebAppSiteControlsBuilder(
+    private val sessionManager: SessionManager,
+    reloadUrlUseCase: SessionUseCases.ReloadUrlUseCase,
+    private val sessionId: String,
+    private val manifest: WebAppManifest
+) : SiteControlsBuilder {
+
+    private val inner = SiteControlsBuilder.CopyAndRefresh(reloadUrlUseCase)
+
+    override fun buildNotification(
+        context: Context,
+        builder: NotificationCompat.Builder,
+        channelId: String
+    ) {
+        inner.buildNotification(context, builder, channelId)
+
+        val isPrivateSession = sessionManager.findSessionById(sessionId)?.private ?: false
+
+        if (!isPrivateSession) { return }
+
+        builder.setSmallIcon(R.drawable.ic_pbm_notification)
+        builder.setContentTitle(context.getString(R.string.pwa_site_controls_title_private, manifest.name))
+    }
+
+    override fun getFilter() = inner.getFilter()
+
+    override fun onReceiveBroadcast(context: Context, session: Session, intent: Intent) = inner.onReceiveBroadcast(context, session, intent)
+}

app/src/main/res/values/strings.xml

@@ -460,6 +460,8 @@
     <string name="collection_open_tabs">Open tabs</string>
     <!-- Text for the menu button to remove a top site -->
     <string name="remove_top_site">Remove</string>
+    <!-- Postfix for private WebApp titles, placeholder is replaced with app name -->
+    <string name="pwa_site_controls_title_private">%1$s (Private Mode)</string>
 
     <!-- History -->
     <!-- Text for the button to clear all history -->