For #1932: Crash on telemetry setting change when unattached (#2124)

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

@@ -4,32 +4,45 @@
 
 package org.mozilla.fenix.settings
 
+import android.content.SharedPreferences
 import android.os.Bundle
 import androidx.appcompat.app.AppCompatActivity
 import androidx.preference.PreferenceFragmentCompat
 import androidx.preference.SwitchPreference
 import org.mozilla.fenix.R
-import org.mozilla.fenix.ext.requireComponents
+import org.mozilla.fenix.ext.components
 import org.mozilla.fenix.utils.Settings
 
 class DataChoicesFragment : PreferenceFragmentCompat() {
 
-    override fun onCreate(savedInstanceState: Bundle?) {
-        super.onCreate(savedInstanceState)
-        (activity as AppCompatActivity).title = getString(R.string.preferences_data_choices)
-        (activity as AppCompatActivity).supportActionBar?.show()
-
-        preferenceManager.sharedPreferences.registerOnSharedPreferenceChangeListener { sharedPreferences, key ->
+    private val preferenceChangeListener =
+        SharedPreferences.OnSharedPreferenceChangeListener { sharedPreferences, key ->
             when (key) {
                 getString(R.string.pref_key_telemetry) -> {
                     if (sharedPreferences.getBoolean(key, Settings.getInstance(requireContext()).isTelemetryEnabled)) {
-                        requireComponents.analytics.metrics.start()
+                        context?.components?.analytics?.metrics?.start()
                     } else {
-                        requireComponents.analytics.metrics.stop()
+                        context?.components?.analytics?.metrics?.stop()
                     }
                 }
             }
         }
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        (activity as AppCompatActivity).title = getString(R.string.preferences_data_choices)
+        (activity as AppCompatActivity).supportActionBar?.show()
+
+        context?.let {
+            preferenceManager.sharedPreferences.registerOnSharedPreferenceChangeListener(preferenceChangeListener)
+        }
+    }
+
+    override fun onDestroy() {
+        context?.let {
+            preferenceManager.sharedPreferences.unregisterOnSharedPreferenceChangeListener(preferenceChangeListener)
+        }
+        super.onDestroy()
     }
 
     override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {