Bluetooth : fix for unexpected discovery summary string changing

- While Visibility timeout setting is never,
  the summary string "Visible to all nearby Bluetooth devices" is shown.
  but if rotating screen or unpairing, pairing actions make the summary
  be changed "Not visible to other Bluetooth devices" or
  "Only visible to paired devices"
- call handleModeChanged() to refresh summary state.

Change-Id: I4b324f2a9530e5e4ca4571f3dd47e8992bdae0cb
Signed-off-by: jhtop.kim <jhtop.kim@samsung.com>