aaudio: cache framesPerBurst and capacity

These do not change after opening the stream so we can
simply return a stored value and avoid querying the device.

Test: atest AAudioTests
Change-Id: I7a66c12bd695fd732194ff0a14ac9c8d9cacf923
diff --git a/media/libaaudio/src/client/AudioStreamInternalCapture.cpp b/media/libaaudio/src/client/AudioStreamInternalCapture.cpp
index 55fc986..5d311fc 100644
--- a/media/libaaudio/src/client/AudioStreamInternalCapture.cpp
+++ b/media/libaaudio/src/client/AudioStreamInternalCapture.cpp
@@ -149,7 +149,7 @@
                 // Calculate frame position based off of the readCounter because
                 // the writeCounter might have just advanced in the background,
                 // causing us to sleep until a later burst.
-                int64_t nextPosition = mAudioEndpoint->getDataReadCounter() + mFramesPerBurst;
+                int64_t nextPosition = mAudioEndpoint->getDataReadCounter() + getFramesPerBurst();
                 wakeTime = mClockModel.convertPositionToLatestTime(nextPosition);
             }
                 break;