Convert manually triggered try runs to use bots without _swarming prefix.

jingle/PRESUBMIT.py

Index: jingle/PRESUBMIT.py
diff --git a/jingle/PRESUBMIT.py b/jingle/PRESUBMIT.py
index 9e62e23dfb9a62994f4460aebbfb5bb8d10ad8bb..ae8a5ba14c874daa968ffa8a9f26fb7109691d19 100644
--- a/jingle/PRESUBMIT.py
+++ b/jingle/PRESUBMIT.py
@@ -11,12 +11,12 @@ for more details on the presubmit API built into gcl.
 def GetPreferredTryMasters(project, change):
   return {
     'tryserver.chromium.linux': {
-      'linux_chromium_rel_swarming': set(['defaulttests']),
+      'linux_chromium_rel': set(['defaulttests']),
     },
     'tryserver.chromium.mac': {
-      'mac_chromium_rel_swarming': set(['defaulttests']),
+      'mac_chromium_rel': set(['defaulttests']),
     },
     'tryserver.chromium.win': {
-      'win_chromium_rel_swarming': set(['defaulttests']),
+      'win_chromium_rel': set(['defaulttests']),
     }
   }