Fix rtcp_sender to support sdes with 31 chunk
Previosly it supported up to only 15 chunks which is a limit for csrcs in an rtp packet.

BUG=None

Review-Url: https://codereview.webrtc.org/2758533002
Cr-Commit-Position: refs/heads/master@{#17274}
diff --git a/webrtc/modules/rtp_rtcp/source/rtcp_packet/sdes.h b/webrtc/modules/rtp_rtcp/source/rtcp_packet/sdes.h
index 31366ad3..46382ac 100644
--- a/webrtc/modules/rtp_rtcp/source/rtcp_packet/sdes.h
+++ b/webrtc/modules/rtp_rtcp/source/rtcp_packet/sdes.h
@@ -28,6 +28,7 @@
     std::string cname;
   };
   static constexpr uint8_t kPacketType = 202;
+  static constexpr size_t kMaxNumberOfChunks = 0x1f;
 
   Sdes();
   ~Sdes() override;
@@ -48,8 +49,6 @@
               RtcpPacket::PacketReadyCallback* callback) const override;
 
  private:
-  static const size_t kMaxNumberOfChunks = 0x1f;
-
   std::vector<Chunk> chunks_;
   size_t block_length_;
 };