Use Jenkinsfile from git instead of static file.

Change-Id: I37b2e2f77810a8f84e6c57c2a0e19d957da9b64a

tools/gate/aiab/seed.groovy

@@ -43,9 +43,12 @@ pipelineJob("treasuremap-aiab") {
         }
 
         definition {
-            cps {
-                script(readFileFromWorkspace("${JOB_BASE}/Jenkinsfile"))
-                sandbox(false)
+            cpsScm {
+                scm {
+                    git('https://review.opendev.org/airship/treasuremap')
+                    scriptPath('tools/gate/aiab/Jenkinsfile')
+                    lightweight(true)
+                }
             }
         }
     }

tools/gate/airsloop/seed.groovy

@@ -80,9 +80,12 @@ pipelineJob('airsloop') {
         }
 
         definition {
-            cps {
-                script(readFileFromWorkspace("tools/gate/airsloop/Jenkinsfile"))
-                sandbox(false)
+            cpsScm {
+                scm {
+                    git('https://review.opendev.org/airship/treasuremap')
+                    scriptPath('tools/gate/airsloop/Jenkinsfile')
+                    lightweight(true)
+                }
             }
         }
     }

tools/gate/seaworthy/seed.groovy

@@ -33,9 +33,12 @@ pipelineJob('Seaworthy') {
         }
 
         definition {
-            cps {
-                script(readFileFromWorkspace("tools/gate/seaworthy/Jenkinsfile"))
-                sandbox(false)
+            cpsScm {
+                scm {
+                    git('https://review.opendev.org/airship/treasuremap')
+                    scriptPath('tools/gate/seaworthy/Jenkinsfile')
+                    lightweight(true)
+                }
             }
         }
     }