Fix auto_level_enable, auto_level_disable; add comments for strings used for ContentDescription.

    <string name="preference_show_face_detection">Show face detection icon</string>

    <string name="preference_show_face_detection_summary">Whether to show an on-screen icon for enabling or disabling face detection</string>

    <string name="face_detection_enable">Enable face detection</string>

    <string name="face_detection_disable">Disable face detection</string>

    <string name="face_detection_enable">Enable face detection</string> <!-- for "ContentDescription" (used for accessibility, e.g., Google Talkback) -->

    <string name="face_detection_disable">Disable face detection</string> <!-- for "ContentDescription" (used for accessibility, e.g., Google Talkback) -->

    <string name="face_detection_enabled">Face detection enabled</string>

    <string name="face_detection_disabled">Face detection disabled</string>

    <string name="preference_show_auto_level">Show auto-level icon</string>

    <string name="preference_show_auto_level_summary">Whether to show an on-screen icon for enabling or disabling auto-level. When auto-level is enabled, photos will be rotated so they are automatically level with the horizon.</string>

    <string name="auto_level_enable">Enable face detection</string>

    <string name="auto_level_disable">Disable face detection</string>

    <string name="auto_level_enable">Enable auto-level</string> <!-- for "ContentDescription" (used for accessibility, e.g., Google Talkback) -->

    <string name="auto_level_disable">Disable auto-level</string> <!-- for "ContentDescription" (used for accessibility, e.g., Google Talkback) -->

    <string name="preference_show_stamp">Show stamp photo icon</string>

    <string name="preference_show_stamp_summary">Whether to show an on-screen icon for enabling or disabling photo stamp</string>

    <string name="stamp_enable">Enable photo stamp</string>

    <string name="stamp_disable">Disable photo stamp</string>

    <string name="stamp_enable">Enable photo stamp</string> <!-- for "ContentDescription" (used for accessibility, e.g., Google Talkback) -->

    <string name="stamp_disable">Disable photo stamp</string> <!-- for "ContentDescription" (used for accessibility, e.g., Google Talkback) -->

    <string name="stamp_enabled">Photo stamp enabled</string>

    <string name="stamp_disabled">Photo stamp disabled</string>