aaudio: preserve requested device ID, fix regression

This fixes a bug that caused the mDeviceId and the mRequestedDeviceId
to be set to a specific device even when UNSPECIFIED was requested.
That led to some streams not getting disconnected when they should.

Bug: 242648766
Test: OboeTester TEST DISCONNECT
Test: OboeTester TEST INPUT
Test: open an MMAP stream and then plug in a headet
Test: it should close the input stream.
Change-Id: I51f0517e719b847f519bb08d3e5b0afb9b4d2f36