[autotest] Support adb_host repair

Implements a basic repair function for adb_host which
runs provision_AndroidUpdate if the device is reachable
via fastboot. The repair image will be retrieved from
global_config or the DB if it is set.

BUG=b:26879108
TEST=local moblab repair.

Change-Id: I26a962c1bf458a8b02ad66efbc2c2bda99530320
Reviewed-on: https://chromium-review.googlesource.com/325519
Commit-Ready: Simran Basi <sbasi@chromium.org>
Tested-by: Simran Basi <sbasi@chromium.org>
Reviewed-by: Kevin Cheng <kevcheng@chromium.org>
diff --git a/frontend/afe/site_rpc_interface.py b/frontend/afe/site_rpc_interface.py
index 074e438..5b625a5 100644
--- a/frontend/afe/site_rpc_interface.py
+++ b/frontend/afe/site_rpc_interface.py
@@ -574,15 +574,18 @@
 
 
 @rpc_utils.route_rpc_to_master
-def get_stable_version(board=stable_version_utils.DEFAULT):
+def get_stable_version(board=stable_version_utils.DEFAULT, android=False):
     """Get stable version for the given board.
 
     @param board: Name of the board.
+    @param android: If True, the given board is an Android-based device. If
+                    False, assume its a Chrome OS-based device.
+
     @return: Stable version of the given board. Return global configure value
              of CROS.stable_cros_version if stable_versinos table does not have
              entry of board DEFAULT.
     """
-    return stable_version_utils.get(board)
+    return stable_version_utils.get(board=board, android=android)
 
 
 @rpc_utils.route_rpc_to_master