advertising: Use new mgmt interface for advertising add

advertising: Use new mgmt interface for advertising add

This patch allows bluetoothd to use the new extended advertising add
mgmt interface if it is available. The new interface will be used by
default, as it allows the client to set advertising intervals, and tx
power if the controller and kernel support extended advertising.

Each new registered advertisement will submit two requests to kernel;
the first sets the advertising parameters for the advertising instance,
and the second sets the advertising data and scan response for the
instance.

The parameters MGMT request will return the tx power selected by the
controller (if applicable), which is propagated to the client via a dbus
Set method.

Note: This patch also fixes a small bug in the packet monitor, where the
tx power value 0xff is considered as "Host has no preference". However,
the spec states this value to be 0x7f. It is corrected in this patch

This change has been tested extensively on Hatch (extended advertising)
and Kukui (no extended advertising) chromebooks. Manual tests do the
following:
- Configure advertisement with custom intervals, tx power with valid and
  invalid values and combinations
- Ensure that with valid parameters, they are propagated and set in hci
  requests. With invalid parameters, ensure that the registration fails.

Automatic tests verify 25 advertising usage scenarios involving single
and multi-advertising registration, over-registration, parameter
validation, etc. These tests don't test new intervals and tx power, but
validate that the new MGMT interface does not regress compatibility in
these 25 scenarios.

Signed-off-by: Anuj Jain <anuj01.jain@samsung.com>
Signed-off-by: Ayush Garg <ayush.garg@samsung.com>