aaudio: fix return code from getTimestamp()

Should be AAUDIO_ERROR_INVALID_STATE if no timestamp available.

Bug: 65447871
Test: test_timestamps.cpp should only print AAUDIO_ERROR_INVALID_STATE
Change-Id: Id9e211ef8fce078514f4348a434e0c003372369c
diff --git a/media/libaaudio/src/legacy/AudioStreamTrack.cpp b/media/libaaudio/src/legacy/AudioStreamTrack.cpp
index d38fe46..09c078c 100644
--- a/media/libaaudio/src/legacy/AudioStreamTrack.cpp
+++ b/media/libaaudio/src/legacy/AudioStreamTrack.cpp
@@ -444,7 +444,9 @@
                                      int64_t *timeNanoseconds) {
     ExtendedTimestamp extendedTimestamp;
     status_t status = mAudioTrack->getTimestamp(&extendedTimestamp);
-    if (status != NO_ERROR) {
+    if (status == WOULD_BLOCK) {
+        return AAUDIO_ERROR_INVALID_STATE;
+    } if (status != NO_ERROR) {
         return AAudioConvert_androidToAAudioResult(status);
     }
     int64_t position = 0;