libaudiohal@aidl: Fix handling of point-to-point connections

Point-to-point connections (analog, HDMI, SPDIF) do not use
a device address. Reflect that in `GenerateUniqueDeviceAddress`.
When looking for a device port by address, check if there is
a connected device, and use the connected device port.

Bug: 300648357
Test: atest audiosystem_tests
(cherry picked from https://android-review.googlesource.com/q/commit:892f7614d957ad62a474c588e1d433962779c22c)
Merged-In: Ic89fe25f1b757d8d95da0cbef09aa55887e62f4f
Change-Id: Ic89fe25f1b757d8d95da0cbef09aa55887e62f4f