Move AudioSystem errorCallback call out from gLock

Since the error callback ends up calling into Java,
there is a potential for a deadlock with Java code
that takes AudioSystem.class lock and calls into
native code that takes gLock in its own turn.

Bug: 152819012
Test: use audio on a phone, also
      killing native audioserver while watching YT,
      also while making cellular calls
Change-Id: Ib288ba96ae2f7b5ab36c1b0a1db4adde487d6a49