PRESUBMIT: Add Android ARM64 and remove Linux TSan

Update the default trybots due to recent changes in the
trybots available.

TBR=tommi@webrtc.org
BUG=chromium:354539

Review URL: https://webrtc-codereview.appspot.com/21619004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6364 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 9ba84d3..45e92e7 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -172,6 +172,7 @@
 
   android_bots = [
       'android',
+      'android_arm64',
       'android_apk',
       'android_apk_rel',
       'android_rel',
@@ -187,7 +188,6 @@
       'linux_baremetal',
       'linux_memcheck',
       'linux_rel',
-      'linux_tsan',
       'linux_tsan2',
   ]
   mac_bots = [