[CQ] Add more experimental Chromium trybots to CQ

TBR=delphick@chromium.org
NOTRY=true

Bug: v8:8058
Change-Id: I7ae59067672a295fb61195ac65226c8cd138d7b9
Reviewed-on: https://chromium-review.googlesource.com/1193284Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55446}

infra/config/cq.cfg

@@ -116,10 +116,18 @@ verifiers {
         name: "cast_shell_android"
         experiment_percentage: 20
       }
+      builders {
+        name: "cast_shell_linux"
+        experiment_percentage: 20
+      }
       builders {
         name: "chromeos_daisy_chromium_compile_only_ng"
         experiment_percentage: 20
       }
+      builders {
+        name: "linux-chromeos-rel"
+        experiment_percentage: 20
+      }
     }
   }
 }