H2AM: reject on non-routable port association

`AudioPolicyInterface::getAudioMixPort` claims to
"Get the attributes of the mix port when connecting to the
given device port."

If the mix port does not route to the device port, it should tell that
it is invalid.

Bug: 367117623
Test: atest CoreAudioHalAidlTest
Flag: com.android.media.audioserver.enable_strict_port_routing_checks
Change-Id: I109a6aa17b844f175376e247cff0eb2178d3ac79