audio: Align Module::getMmapPolicyInfos behavior with legacy

When there are no device ports supporting MMAP,
Module::getMmapPolicyInfos have to return 'Policy::NEVER'
so that the AAudio code does not attempt to use
the AAudio service. This aligns with the use of sysprops
by the HIDL implementation.

Update AudioCoreModule#GetMmapPolicyInfos test to use
the same logic for determining MMAP support as the framework
uses.

This makes CtsNativeMediaAAudioTest cases passing with
the AIDL HAL on Cuttlefish.

Bug: 302049825
Test: atest VtsHalAudioCoreTargetTest
Test: atest CtsNativeMediaAAudioTest [w/AIDL enabled on CF]
Change-Id: Ie58c408f6f648a8a03b6a5d92118b90061389c50