Extract "Devices" preference category title to string resource

Fixes #4621
// FREEBIE

res/values/strings.xml

@@ -973,6 +973,7 @@
     <string name="preferences__conversation_length_limit">Conversation length limit</string>
     <string name="preferences__trim_all_threads_now">Trim all threads now</string>
     <string name="preferences__scan_through_all_conversation_threads_and_enforce_conversation_length_limits">Scan through all conversation threads and enforce conversation length limits</string>
+    <string name="preferences__devices">Devices</string>
     <string name="preferences__light_theme">Light</string>
     <string name="preferences__dark_theme">Dark</string>
     <string name="preferences__appearance">Appearance</string>

res/xml/preferences.xml

@@ -22,7 +22,7 @@
                 android:icon="?pref_ic_chats"/>
 
     <Preference android:key="preference_category_devices"
-                android:title="Devices"
+                android:title="@string/preferences__devices"
                 android:icon="?pref_ic_devices"/>
 
     <Preference android:key="preference_category_advanced"