Bluetooth: Enable system processes to set bluetooth properties

ANT and BT is part of the same wcnsss subsystem and hence libbt-vendor
is being used by both ANT and BT stack for hardware initialization.
ANT stack runs in system permission which loads libbt-vendor which in turn
needs write access to bluetooth. properties.

Change-Id: I29a9b74504f1c03b98db3cddb2a53399f4b6115b
Bluetooth: Introduce new property type and permission

Introduce new property type and allow system and bluetooth
processes to set these properties so that transport layer of
AND and BT stack can set these properties for chip initialization
part

Change-Id: I7735d4743d8b43ea935584901d5aa330df965868
CRs-fixed: 580768