Add watchlist for webrtc/media + add solenberg@

- Add watchlist for webrtc/media.
- Add/remove myself from lists.

NOTRY=True

Review URL: https://codereview.webrtc.org/1887983004

Cr-Commit-Position: refs/heads/master@{#12375}

WATCHLISTS

@@ -38,6 +38,9 @@
     'call': {
       'filepath': 'webrtc/call/.*',
     },
+    'media': {
+      'filepath': 'webrtc/media/.*',
+    },
     'video': {
       'filepath': 'webrtc/video/.*',
     },
@@ -111,10 +114,10 @@
              'pbos@webrtc.org',
              'solenberg@webrtc.org',
              'stefan@webrtc.org'],
+    'media': [solenberg@webrtc.org],
     'video': ['mflodman@webrtc.org',
               'pbos@webrtc.org',
               'perkj@webrtc.org',
-              'solenberg@webrtc.org',
               'stefan@webrtc.org',
               'video-team@agora.io',
               'yujie.mao@webrtc.org',