[CQ] Add verify-csa bot experimentally to CQ

infra/config/cq.cfg

 # See http://luci-config.appspot.com/schemas/projects/refs:cq.cfg for the
 # documentation of this file format.
 
 version: 1
 cq_name: "v8"
 cq_status_url: "https://chromium-cq-status.appspot.com"
 commit_burst_delay: 60
 max_commit_burst: 1
 
 rietveld {
@@ skipping 27 matching lines @@
       builders { name: "v8_linux64_gyp_rel_ng" }
       builders {
         name: "v8_linux64_gyp_rel_ng_triggered"
         triggered_by: "v8_linux64_gyp_rel_ng"
       }
       builders { name: "v8_linux64_rel_ng" }
       builders {
         name: "v8_linux64_rel_ng_triggered"
         triggered_by: "v8_linux64_rel_ng"
       }
+      builders {
+        name: "v8_linux64_verify_csa_rel_ng"
+        experiment_percentage: 100
+      }
       builders { name: "v8_linux_arm64_rel_ng" }
       builders {
         name: "v8_linux_arm64_rel_ng_triggered"
         triggered_by: "v8_linux_arm64_rel_ng"
       }
       builders { name: "v8_linux_arm_rel_ng" }
       builders {
         name: "v8_linux_arm_rel_ng_triggered"
         triggered_by: "v8_linux_arm_rel_ng"
       }
@@ skipping 52 matching lines @@
       builders {
         name: "win_chromium_compile_dbg_ng"
         experiment_percentage: 100
       }
     }
   }
 
   sign_cla {}
 }