mediaplayer: get/set PlaybackRate only when AudioSink has been opened.

Change-Id: I676567fc029b9f82d039990e629374bd48168cec
diff --git a/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.cpp b/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.cpp
index 6b8f99c..007a335 100644
--- a/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.cpp
+++ b/media/libmediaplayerservice/nuplayer/NuPlayerRenderer.cpp
@@ -146,7 +146,7 @@
         return OK;
     }
 
-    if (mAudioSink != NULL) {
+    if (mAudioSink != NULL && mAudioSink->ready()) {
         status_t err = mAudioSink->setPlaybackRate(rate);
         if (err != OK) {
             return err;
@@ -172,7 +172,7 @@
 }
 
 status_t NuPlayer::Renderer::onGetPlaybackSettings(AudioPlaybackRate *rate /* nonnull */) {
-    if (mAudioSink != NULL) {
+    if (mAudioSink != NULL && mAudioSink->ready()) {
         status_t err = mAudioSink->getPlaybackRate(rate);
         if (err == OK) {
             if (!isAudioPlaybackRateEqual(*rate, mPlaybackSettings)) {
@@ -1378,7 +1378,7 @@
         mPaused = false;
 
         // configure audiosink as we did not do it when pausing
-        if (mAudioSink != NULL) {
+        if (mAudioSink != NULL && mAudioSink->ready()) {
             mAudioSink->setPlaybackRate(mPlaybackSettings);
         }