support peripheral mode feature to connect iphone to android device.

enable BLE_PERIPHERAL_MODE_SUPPORT flag and fix the bug
the discoverability flag is not set in advertisement packet,
which cause the central device(iphone) can not find android device
during scan.
use displayOnly IO cap for dory, so dory can display the pin,
and the iphone(central device) will input the pin.
bug:12797572

Change-Id: Ie15ea9e340e3692df846399b9a85aa6d2a97eba7