Clean up a few option strings under the Advanced settings

    <!-- Title of an option for usability study mode -->

    <string name="prefs_usability_study_mode">Usability study mode</string>

    <!-- Title of the settings for key long press delay -->

    <string name="prefs_key_longpress_timeout_settings">Key long press delay settings</string>

    <!-- Title of the settings for keypress vibration duration -->

    <string name="prefs_keypress_vibration_duration_settings">Keypress vibration duration settings</string>

    <!-- Title of the settings for keypress sound volume -->

    <string name="prefs_keypress_sound_volume_settings">Keypress sound volume settings</string>

    <!-- Title of the settings for key long press delay [CHAR LIMIT=30] -->

    <string name="prefs_key_longpress_timeout_settings">Key long press delay</string>

    <!-- Title of the settings for keypress vibration duration [CHAR LIMIT=30] -->

    <string name="prefs_keypress_vibration_duration_settings">Keypress vibration duration</string>

    <!-- Title of the settings for keypress sound volume [CHAR LIMIT=30] -->

    <string name="prefs_keypress_sound_volume_settings">Keypress sound volume</string>

    <!-- Title of the settings for reading an external dictionary file -->

    <string name="prefs_read_external_dictionary">Read external dictionary file</string>

    <!-- Message to show when there are no files to install as an external dictionary [CHAR LIMIT=100] -->