iOS: add type to peer connection local streams

BUG=

Review-Url: https://codereview.webrtc.org/2249173002
Cr-Commit-Position: refs/heads/master@{#13825}
diff --git a/AUTHORS b/AUTHORS
index e9e9d66..6d1ee96 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -21,6 +21,7 @@
 Manish Jethani <manish.jethani@gmail.com>
 Martin Storsjo <martin@martin.st>
 Matthias Liebig <matthias.gcode@gmail.com>
+Maxim Potapov <vopatop.skam@gmail.com>
 Pali Rohar
 Paul Kapustin <pkapustin@gmail.com>
 Rafael Lopez Diez <rafalopezdiez@gmail.com>