For #1998 - Removes stable flag in entering fullscreen navigation

app/src/main/java/org/mozilla/fenix/browser/BrowserFragment.kt

@@ -51,7 +51,6 @@ import mozilla.components.feature.sitepermissions.SitePermissionsFeature
 import mozilla.components.feature.sitepermissions.SitePermissionsRules
 import mozilla.components.support.base.feature.BackHandler
 import mozilla.components.support.base.feature.ViewBoundFeatureWrapper
-import mozilla.components.support.ktx.android.view.enterToImmersiveMode
 import mozilla.components.support.ktx.android.view.exitImmersiveModeIfNeeded
 import mozilla.components.support.ktx.kotlin.toUri
 import org.mozilla.fenix.BrowsingModeManager
@@ -77,6 +76,7 @@ import org.mozilla.fenix.components.toolbar.ToolbarUIView
 import org.mozilla.fenix.components.toolbar.ToolbarViewModel
 import org.mozilla.fenix.customtabs.CustomTabsIntegration
 import org.mozilla.fenix.ext.components
+import org.mozilla.fenix.ext.enterToImmersiveMode
 import org.mozilla.fenix.ext.nav
 import org.mozilla.fenix.ext.requireComponents
 import org.mozilla.fenix.ext.urlToTrimmedHost

app/src/main/java/org/mozilla/fenix/ext/Activity.kt

@@ -0,0 +1,21 @@
+/* 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.ext
+
+import android.app.Activity
+import android.view.View
+import android.view.WindowManager
+
+/**
+ * Attempts to call immersive mode using the View to hide the status bar and navigation buttons.
+ */
+fun Activity.enterToImmersiveMode() {
+    window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON)
+    window.decorView.systemUiVisibility = (View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
+            or View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
+            or View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
+            or View.SYSTEM_UI_FLAG_FULLSCREEN
+            or View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY)
+}