Do not try to unregister APC multiple time

If audioRecord.release() is called explicitly, APC DP is released.
When the AudioRecord.finalizer() is called by the JVM, the APC DP would
be released again, leading to misleading error message.

Bug: 131064451
Test: call AudioRecord release and check that the finalizer do not log a
      release failure
Change-Id: Ia7092274ea8ac8e0a6754dfe2541f823f650384d
Signed-off-by: Kevin Rocard <krocard@google.com>