Devserver update rpc: translate xBuddy paths.

If an update request starts with 'xbuddy' the rest of the path will be
translated to a directory within the devserver's static_dir before being
passed onto the normal update call.

BUG=chromium:261671
TEST=Effectively None, as there aren't any scripts that use the update
rpc with xBuddy yet. :(

Can call http://host:port/update/xbuddy/board/version/ to see that the
translation happens, but without the xml, this isn't meaningful yet.

Change-Id: I072ba04045a30b3c7d03d67556f9f9d0c7af41ec
Reviewed-on: https://gerrit.chromium.org/gerrit/63282
Reviewed-by: Chris Sosa <sosa@chromium.org>
Commit-Queue: Joy Chen <joychen@chromium.org>
Reviewed-by: Joy Chen <joychen@chromium.org>
Tested-by: Joy Chen <joychen@chromium.org>
2 files changed