Get/Set IO capabilities of Bluetooth device

Adds the backend service methods to call into Bluetooth native
stack and store/retrieve Bluetooth IO capabilities of the device. This
allows a user to use different flows of pairing based on their
device.

Bug: 36015413
Test: Used a test activity to set different values and pair accordingly.
Change-Id: I96690f88ea5ca14655e187be416c5066eb072217
(cherry picked from commit cd84c54a0ac6cc549673631eefbde6680a189527)