[chromium.chromiumos] Update extra vpython pins.

The currently pinned version doesn't understand SHA256 package IDs.
Update these pins to the currently deployed vpython version.

R=bpastene@chromium.org, dgarrett@chromium.org

Bug: 878994
Change-Id: I8e5dd3023fd91f3e8f2155638d3464b23f05906f
Reviewed-on: https://chromium-review.googlesource.com/c/1312976Reviewed-by: Ben Pastene <bpastene@chromium.org>
Commit-Queue: Robbie Iannucci <iannucci@chromium.org>
Cr-Commit-Position: refs/heads/master@{#604645}

testing/buildbot/chromium.chromiumos.json

@@ -251,7 +251,7 @@
             {
               "cipd_package": "infra/tools/luci/vpython/linux-amd64",
               "location": "vpython_dir_linux_amd64",
-              "revision": "git_revision:e1abc57be62d198b5c2f487bfb2fa2d2eb0e867c"
+              "revision": "git_revision:9a931a5307c46b16b1c12e01e8239d4a73830b89"
             }
           ],
           "dimension_sets": [

testing/buildbot/chromium.fyi.json

@@ -3269,7 +3269,7 @@
             {
               "cipd_package": "infra/tools/luci/vpython/linux-amd64",
               "location": "vpython_dir_linux_amd64",
-              "revision": "git_revision:e1abc57be62d198b5c2f487bfb2fa2d2eb0e867c"
+              "revision": "git_revision:9a931a5307c46b16b1c12e01e8239d4a73830b89"
             }
           ],
           "dimension_sets": [

testing/buildbot/test_suites.pyl

@@ -408,7 +408,7 @@
             {
               "cipd_package": 'infra/tools/luci/vpython/linux-amd64',
               'location': 'vpython_dir_linux_amd64',
-              'revision': 'git_revision:e1abc57be62d198b5c2f487bfb2fa2d2eb0e867c',
+              'revision': 'git_revision:9a931a5307c46b16b1c12e01e8239d4a73830b89',
             }
           ],
           'shards': 3,
@@ -449,7 +449,7 @@
             {
               "cipd_package": 'infra/tools/luci/vpython/linux-amd64',
               'location': 'vpython_dir_linux_amd64',
-              'revision': 'git_revision:e1abc57be62d198b5c2f487bfb2fa2d2eb0e867c',
+              'revision': 'git_revision:9a931a5307c46b16b1c12e01e8239d4a73830b89',
             }
           ],
         },