VT: do not remove a rx session even if ECONNREFUSED occurred.

[Problem] rx session removed if recvfrom() returned
 -1 with ECONNREFUSED reason.
[Cause] ECONNREFUSED can be occurred while calling
  recvfrom() after sendto() for a rtcp packet such
  as RR and TMMBR if remote side didn't open a socket yet.
[Solution] rx session should not be removed even if
  remote device didn't ready to receive a packet yet.

Bug: 196252321

Change-Id: I22b1fbd660a930aaac5e0952fb81cf0537822b77
Signed-off-by: Gaurav <gaurav.tiw@samsung.com>
(cherry picked from commit a261106c95bf8d3de4dc06fa3806f8c45bd91a2b)

media/libstagefright/rtsp/ARTPConnection.cpp

diff --git a/media/libstagefright/rtsp/ARTPConnection.cpp b/media/libstagefright/rtsp/ARTPConnection.cpp
index ffccbb1..0bd342a 100644
--- a/media/libstagefright/rtsp/ARTPConnection.cpp
+++ b/media/libstagefright/rtsp/ARTPConnection.cpp
@@ -508,8 +508,6 @@
                     if (n != (ssize_t)buffer->size()) {
                         ALOGW("failed to send RTCP TMMBR (%s).",
                                 n >= 0 ? "connection gone" : strerror(errno));
-
-                        it = mStreams.erase(it);
                         continue;
                     }
                 }
@@ -560,8 +558,6 @@
                 if (n != (ssize_t)buffer->size()) {
                     ALOGW("failed to send RTCP receiver report (%s).",
                             n >= 0 ? "connection gone" : strerror(errno));
-
-                    it = mStreams.erase(it);
                     continue;
                 }
 
@@ -621,7 +617,14 @@
     } while (nbytes < 0 && errno == EINTR);
 
     if (nbytes <= 0) {
-        return -ECONNRESET;
+        ALOGW("failed to recv rtp packet. cause=%s", strerror(errno));
+        // ECONNREFUSED may happen in next recvfrom() calling if one of
+        // outgoing packet can not be delivered to remote by using sendto()
+        if (errno == ECONNREFUSED) {
+            return -ECONNREFUSED;
+        } else {
+            return -ECONNRESET;
+        }
     }
 
     buffer->setRange(0, nbytes);
@@ -665,6 +668,10 @@
                     pRemoteRTCPAddr, sizeSockSt);
         } while (n < 0 && errno == EINTR);
 
+        if (n < 0) {
+            ALOGW("failed to send rtcp packet. cause=%s", strerror(errno));
+        }
+
         return n;
 }