Change CI env to JENKINS_CI

scripts/release.js

 }
 
 function validateEnv() {
-  if (!process.env.CI) {
+  if (!process.env.JENKINS_CI) {
     throw new Error(`releasing is only available from CI`);
   }
 

scripts/test-e2e.js

   const prefix = android ? `android.emu` : `ios.sim`;
   const suffix = release ? `release` : `debug`;
   const configuration = `${prefix}.${suffix}`;
-  const cleanup = process.env.CI ? `--cleanup` : ``;
+  const cleanup = process.env.JENKINS_CI ? `--cleanup` : ``;
 
   if (!skipBuild) {
     exec.execSync(`detox build --configuration ${configuration}`);