Roll src/third_party/cros_system_api/ b2cdc6cc7..e18eab01d (3 commits)

https://chromium.googlesource.com/chromiumos/platform2/system_api.git/+log/b2cdc6cc701d..e18eab01d2d4

$ git log b2cdc6cc7..e18eab01d --date=short --no-merges --format='%ad %ae %s'
2020-02-11 dverkamp system_api: vm_concierge: add disk type to ListVmDisks
2020-02-04 dverkamp system_api: vm_concierge: add min disk size field
2020-01-28 acostinas system_api: Add D-Bus constants for System-proxy

Created with:
  roll-dep src/third_party/cros_system_api

Bug: chromium:1042624
Change-Id: I27126f1e599e10aba375a87cd824ac53d2ab8555
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2054104Reviewed-by: Pavol Marko <pmarko@chromium.org>
Commit-Queue: Andreea-Elena Costinas <acostinas@google.com>
Cr-Commit-Position: refs/heads/master@{#741437}

DEPS

@@ -876,7 +876,7 @@ deps = {
 
   # For Linux and Chromium OS.
   'src/third_party/cros_system_api': {
-      'url': Var('chromium_git') + '/chromiumos/platform2/system_api.git' + '@' + 'b2cdc6cc701d9489873acc037c0bcf9e13237ab5',
+      'url': Var('chromium_git') + '/chromiumos/platform2/system_api.git' + '@' + 'e18eab01d2d46ac46ad7a6b89df4296bf0065381',
       'condition': 'checkout_linux',
   },