buffet: Add support for DEVICE_DELETED XMPP notification

When DEVICE_DELETED notification is received over XMPP channel,
buffet will remove any cloud registration information (credentials,
robot account) and close server connections (XMPP channel, etc).

BUG=brillo:1215
TEST=`FEATURES=test emerge-link buffet`
     Test manually on the device.

Change-Id: I86e19659b9fbc06685bcabb6c659a633e797cae5
Reviewed-on: https://chromium-review.googlesource.com/281666
Tested-by: Alex Vakulenko <avakulenko@chromium.org>
Trybot-Ready: Alex Vakulenko <avakulenko@chromium.org>
Reviewed-by: Vitaly Buka <vitalybuka@chromium.org>
Commit-Queue: Alex Vakulenko <avakulenko@chromium.org>
5 files changed
tree: 2adc150eb4f8c3baf8b4fd7387f5bc07beb72463
  1. buffet/