WIP: Add auto-sheriff.appspot.com code to Blink

Tools/AutoSheriff/index.yaml

+indexes:
+
+# AUTOGENERATED
+
+# This index.yaml is automatically updated whenever the dev_appserver
+# detects that a new type of query is run.  If you want to manage the
+# index.yaml file manually, remove the above marker line (the line
+# saying "# AUTOGENERATED").  If you want to manage some indexes
+# manually, move them above the marker line.  The index.yaml file is
+# automatically uploaded to the admin console when you next deploy
+# your application using appcfg.py.
+
+- kind: _AE_Pipeline_Record
+  properties:
+  - name: is_root_pipeline
+  - name: start_time
+    direction: desc