Unify advertising API (2/3)

This patch unifies advertising API. On startup, if VSC multi advertising
is avaliable, it will be used, otherwise
BleAdvertiserLegacyHciInterfaceImpl will be used, which provides one
advertising instance.

Test: sl4a tests are passing, all proper tests updated accordingly
Change-Id: I02d3996f694beb6614d342d6c15a8c27b7b7274a
1 file changed