Clean up unused Call Manager strings

         For example, they may have alerts just once or every 2 or 15 minutes.  [CHAR LIMIT=30] -->

    <string name="repeat_title">Repeat</string>

    <!-- Call Manager enable settings title.  [CHAR LIMIT=50] -->

    <string name="call_manager_enable_title">Enable Call Manager</string>

    <!-- Call Manager enable settings summary.  [CHAR LIMIT=80] -->

    <string name="call_manager_enable_summary">Allow this service to manage how your calls are made.</string>

    <!-- Call Manager settings title.  [CHAR LIMIT=50] -->

    <string name="call_manager_title">Call Manager</string>

    <!-- Call Manager settings summary.  [CHAR LIMIT=50] -->

    <string name="call_manager_summary"><xliff:g id="app">%1$s</xliff:g></string>

    <!-- Cell Broadcast settings title.  [CHAR LIMIT=50] -->

    <string name="cell_broadcast_settings">Wireless emergency alerts</string>

    <!-- Network operators settings title.  [CHAR LIMIT=50] -->