Update DND duration setting string

    <string name="zen_mode_behavior_settings_title">Exceptions</string>

    <!-- Do not disturb: Title for the dnd duration setting (user can specify how long dnd will last when toggling dnd on from qs or settings) [CHAR LIMIT=30] -->

    <string name="zen_mode_duration_settings_title">Duration</string>

    <string name="zen_mode_duration_settings_title">Default duration</string>

    <!-- Do not disturb: Instructions indicating what types of sounds can bypass DND. [CHAR LIMIT=52] -->

    <string name="zen_mode_behavior_allow_title">Allow sounds and vibrations from</string>