ligbaaudio: Fix pause, flush and getXRunCount for input streams.

Bug: 37941092
Bug: 37943598
Test: input_monitor_callback.cpp

Change-Id: Ifc2ea526e4722063e03956bd5f0747adc49ba6ee
Signed-off-by: Phil Burk <philburk@google.com>
diff --git a/media/libaaudio/include/aaudio/AAudio.h b/media/libaaudio/include/aaudio/AAudio.h
index 8498950..c21caa4 100644
--- a/media/libaaudio/include/aaudio/AAudio.h
+++ b/media/libaaudio/include/aaudio/AAudio.h
@@ -507,6 +507,9 @@
  * Use AAudioStream_Start() to resume playback after a pause.
  * After this call the state will be in AAUDIO_STREAM_STATE_PAUSING or AAUDIO_STREAM_STATE_PAUSED.
  *
+ * This will return AAUDIO_ERROR_UNIMPLEMENTED for input streams.
+ * For input streams use AAudioStream_requestStop().
+ *
  * @param stream reference provided by AAudioStreamBuilder_openStream()
  * @return AAUDIO_OK or a negative error.
  */
@@ -519,6 +522,8 @@
  * Frame counters are not reset by a flush. They may be advanced.
  * After this call the state will be in AAUDIO_STREAM_STATE_FLUSHING or AAUDIO_STREAM_STATE_FLUSHED.
  *
+ * This will return AAUDIO_ERROR_UNIMPLEMENTED for input streams.
+ *
  * @param stream reference provided by AAudioStreamBuilder_openStream()
  * @return AAUDIO_OK or a negative error.
  */
@@ -704,6 +709,9 @@
  *
  * An underrun or overrun can cause an audible "pop" or "glitch".
  *
+ * Note that some INPUT devices may not support this function.
+ * In that case a 0 will always be returned.
+ *
  * @param stream reference provided by AAudioStreamBuilder_openStream()
  * @return the underrun or overrun count
  */