For #8743: Fix baseBrowserFragment crash

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

@@ -460,10 +460,12 @@ abstract class BaseBrowserFragment : Fragment(), UserInteractionHandler, Session
 
     private fun adjustBackgroundAndNavigate(directions: NavDirections) {
         context?.let {
-            engineView.captureThumbnail { bitmap ->
-                viewLifecycleOwner.lifecycleScope.launch {
-                    // isAdded check is necessary because of a bug in viewLifecycleOwner. See AC#3828
-                    if (!this@BaseBrowserFragment.isAdded) return@launch
+            viewLifecycleOwner.lifecycleScope.launch {
+                // isAdded check is necessary because of a bug in viewLifecycleOwner. See AC#3828
+                if (!this@BaseBrowserFragment.isAdded) return@launch
+
+                engineView.captureThumbnail { bitmap ->
+                    if (!this@BaseBrowserFragment.isAdded) return@captureThumbnail
 
                     // If the bitmap is null, the best we can do to reduce the flash is set transparent
                     swipeRefresh.background = bitmap?.toDrawable(it.resources)