audio policy: fix canBeSpatialized()

Allow to create a Spatializer controller even if the spatializer
output profile can only be routed to devices not connected at boot time.
Done by fixing AudioPolicyManager::getSpatializerOutputProfile() to
only consider available devices if a specific device list is passed as
argument.

Bug: 234049185
Test: spatial audio playback on Bluetooth
Change-Id: I34a8b1e2a2344f9f5ac5b637d9d344a29537fe33