VT: ARTPConnection: added an event to notify first-rtcp packet.

[Related JIRA] RAMEN9610-4400

[Problem] Call downgrade is not triggered from UE if there is no
rtcp packet received even call is started long time ago.

[Cause] There is no logic for auto-downgrade if there is no any single packet.

[Solution] A new logic for auto-downgrade implemented both
StagefrightPlayer and IMSService.

Bug: 121230209
Change-Id: I44bf7131ba2cdb7a1c8760b62ea81427b43afcb1
Signed-off-by: Byeongjo Park <bjo.park@samsung.com>
diff --git a/media/libmediaplayerservice/nuplayer/RTPSource.cpp b/media/libmediaplayerservice/nuplayer/RTPSource.cpp
index 57b6c59..d4d5bef 100644
--- a/media/libmediaplayerservice/nuplayer/RTPSource.cpp
+++ b/media/libmediaplayerservice/nuplayer/RTPSource.cpp
@@ -382,7 +382,7 @@
             }
 
             int32_t IMSRxNotice;
-            if (msg->findInt32("IMS-Rx-notice", &IMSRxNotice)) {
+            if (msg->findInt32("rtcp-event", &IMSRxNotice)) {
                 int32_t payloadType, feedbackType;
                 CHECK(msg->findInt32("payload-type", &payloadType));
                 CHECK(msg->findInt32("feedback-type", &feedbackType));