[fenix] For https://github.com/mozilla-mobile/fenix/issues/15263: Properly update open links in app preference.

app/src/main/java/org/mozilla/fenix/settings/SettingsFragment.kt

@@ -321,6 +321,8 @@ class SettingsFragment : PreferenceFragmentCompat() {
         val preferenceRemoteDebugging = findPreference<Preference>(debuggingKey)
         val preferenceMakeDefaultBrowser =
             requirePreference<Preference>(R.string.pref_key_make_default_browser)
+        val preferenceOpenLinksInExternalApp =
+            findPreference<Preference>(getPreferenceKey(R.string.pref_key_open_links_in_external_app))
 
         preferencePrivateBrowsing.icon.mutate().apply {
             setTint(requireContext().getColorFromAttr(R.attr.primaryText))
@@ -345,6 +347,8 @@ class SettingsFragment : PreferenceFragmentCompat() {
         preferenceMakeDefaultBrowser.onPreferenceClickListener =
             getClickListenerForMakeDefaultBrowser()
 
+        preferenceOpenLinksInExternalApp?.onPreferenceChangeListener = SharedPreferenceUpdater()
+
         val preferenceFxAOverride =
             findPreference<Preference>(getPreferenceKey(R.string.pref_key_override_fxa_server))
         val preferenceSyncOverride =