audio flinger: handle race condition in AudioRecord creation

A rare race condition can cause a failure to create an AudioRecord if
two creation requests are processed concurrently and thread preemption happens
at a specific time within the sequence between audioflinger and
audio policy manager.

This CL implements a retry mechanism on client side when this particular failure
is detected.

Bug: 161656190
Test: Regression tests for audio capture use cases.
Test: CTS tests for AudiRecord
Change-Id: I155ee4899baeec21e10a1141cb9e323cbc8aa23b
diff --git a/services/audioflinger/Tracks.cpp b/services/audioflinger/Tracks.cpp
index c92bce5..ed285da 100644
--- a/services/audioflinger/Tracks.cpp
+++ b/services/audioflinger/Tracks.cpp
@@ -2229,7 +2229,8 @@
         RecordThread *recordThread = (RecordThread *)thread.get();
         return recordThread->start(this, event, triggerSession);
     } else {
-        return BAD_VALUE;
+        ALOGW("%s track %d: thread was destroyed", __func__, portId());
+        return DEAD_OBJECT;
     }
 }