wifi(implementation): Add iface combo for 2018

Changes in the CL:
a) Added iface combo for 2018 using a new feature flag.
b) Added a generic algorithm to determine if an iface can be created or
not based on the iface combos supported. This is needed because we now
have to support 3 different combos (2016, 2017, 2018) in the HAL.
The current iface creation logic is hard to adapt to these 3 varying combos.

Bug: 65671875
Bug: 69863101
Test: ./hardware/interfaces/wifi/1.2/default/tests/runtests.sh
Change-Id: Iff8737843abee3d03567930e9faba775eaa82e07