Roll src/third_party/cros_system_api/ a4d130010..2302d2194 (3 commits)

https://chromium.googlesource.com/chromiumos/platform2/system_api.git/+log/a4d130010ec6..2302d21944c8

$ git log a4d130010..2302d2194 --date=short --no-merges --format='%ad %ae %s'
2020-02-20 kevinptt runtime_probe: Modify probing type of wireless
2020-02-29 michaelfsun system_api: Add CRAS media player D-Bus constants
2020-02-26 juwa vm_tools: add extensions to Application message

Created with:
  roll-dep src/third_party/cros_system_api

Bug: b:147365563
Change-Id: Ieee9f156c4a834b8f71ce2bd34cd8713c1a670cf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2081187Reviewed-by: Jenny Zhang <jennyz@chromium.org>
Commit-Queue: Michael Sun <michaelfsun@google.com>
Cr-Commit-Position: refs/heads/master@{#746597}

DEPS

@@ -878,7 +878,7 @@ deps = {
 
   # For Linux and Chromium OS.
   'src/third_party/cros_system_api': {
-      'url': Var('chromium_git') + '/chromiumos/platform2/system_api.git' + '@' + 'a4d130010ec6953e722978d879f2f96fa0e155d3',
+      'url': Var('chromium_git') + '/chromiumos/platform2/system_api.git' + '@' + '2302d21944c881abf8897f72319206277b505526',
       'condition': 'checkout_linux',
   },