Roll src/third_party/cros_system_api/ 693e848cd..9a5d5fab3 (2 commits)

https://chromium.googlesource.com/chromiumos/platform2/system_api.git/+log/693e848cded9..9a5d5fab32aa

$ git log 693e848cd..9a5d5fab3 --date=short --no-merges --format='%ad %ae %s'
2018-11-06 joelhockey vm_tools: seneschal: Add support for Unshare
2018-11-01 chirantan vm_tools: concierge: Remove StartContainer method

Created with:
  roll-dep src/third_party/cros_system_api

Change-Id: I73b23667ce4168d6a6d5c184376eda856ab15b14
Reviewed-on: https://chromium-review.googlesource.com/c/1337137Reviewed-by: Sam McNally <sammc@chromium.org>
Commit-Queue: Joel Hockey <joelhockey@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608283}

DEPS

@@ -670,7 +670,7 @@ deps = {
 
   # For Linux and Chromium OS.
   'src/third_party/cros_system_api': {
-      'url': Var('chromium_git') + '/chromiumos/platform2/system_api.git' + '@' + '693e848cded93bf487a75519e185bc8b73cc1bce',
+      'url': Var('chromium_git') + '/chromiumos/platform2/system_api.git' + '@' + '9a5d5fab32aad57e79f27bc5950fcc343467a474',
       'condition': 'checkout_linux',
   },