aaudio: plug some resource leaks

Close some file descriptors for shared memory that were not getting closed.

Bug: 37947848
Test: see bug for test procedure
Change-Id: Icdc13188b0a49d08b67babff0852c3a4eda8fd2b
Signed-off-by: Phil Burk <philburk@google.com>
diff --git a/services/oboeservice/AAudioServiceStreamMMAP.h b/services/oboeservice/AAudioServiceStreamMMAP.h
index a8e63a6..fe75a10 100644
--- a/services/oboeservice/AAudioServiceStreamMMAP.h
+++ b/services/oboeservice/AAudioServiceStreamMMAP.h
@@ -127,6 +127,7 @@
     MonotonicCounter                    mFramesWritten;
     MonotonicCounter                    mFramesRead;
     int32_t                             mPreviousFrameCounter = 0;   // from HAL
+    int                                 mAudioDataFileDescriptor = -1;
 
     // Interface to the AudioFlinger MMAP support.
     android::sp<android::MmapStreamInterface> mMmapStream;