Disable NetworkListenersARC and WebRTCPeerConnCameraVP8 on chromeos-kevin-rel tester.

Looks like they're the only remaining tast test that fails:
https://chromium-swarm.appspot.com/task?id=429a15ecadd81410

Bug: 916367, 866062
Change-Id: If1368f981f788f99def300c50e2539fffc783e48
Reviewed-on: https://chromium-review.googlesource.com/c/1434795Reviewed-by: Achuith Bhandarkar <achuith@chromium.org>
Commit-Queue: Ben Pastene <bpastene@chromium.org>
Cr-Commit-Position: refs/heads/master@{#625835}

chromeos/BUILD.gn

@@ -281,7 +281,12 @@ if (is_cros_chrome_sdk) {
   }
   tast_test("chrome_kevin_tast_tests") {
     # Tests that fail on Kevin devices.
-    tast_disabled_tests = [ "arc.Boot" ]  # crbug.com/916367
+    tast_disabled_tests = [
+      # Disabled due to misleading USE flags on full boards. crbug.com/916367
+      "arc.Boot",
+      "security.NetworkListenersARC",
+      "video.WebRTCPeerConnCameraVP8",  # crbug.com/923061
+    ]
   }
 
   group("cros_chrome_deploy") {