Set the value of using_dynamic_iface_combination_

in the WifiChip constructor.

gTest suite currently cannot mock the legacy HAL
call for getSupportedIfaceConcurrencyMatrix.
If we set using_dynamic_iface_combination_ to true
in the unit tests, we can avoid making this call.

Bug: 271914366
Test: ./runtests.sh # gTest
Test: atest VtsHalWifiChipTargetTest # VTS
Change-Id: Ic43daab6ff5fdc5f78af614ad775f436fbbe8726