audio: Allow built-in strategies to omit the 'id' attribute

For built-in strategies, the 'id' can be set from the name.
This corrects the behavior introduced by aosp/3016651 which
requires product strategies to have the 'id' field, however
restricting it to the IDs from the vendor pool only.

Bug: 385268928
Test: atest VtsHalAudioCoreTargetTest
Change-Id: I3262b626bdbc2b3552695193aaaaa657befec06d