aaudio: disable MMAP mode by not creating AAudioService

Only Legacy mode will work, which uses AudioFlinger.

Note that another CL with the same ID in oc-mr1-dev is used to prevent
AAudio MMAP from being disabled in MR1 and master.

Bug: 65280854
Bug: 65262790
Test: See bugs. Any attempt to use MMAP will fail to open the service.
Merged-In: Ic68d136c99c16134aa704495311ab25285fd76a9
Change-Id: Ic68d136c99c16134aa704495311ab25285fd76a9