Fix "java is not defined" on Apps Script V8

ReferenceError: java is not defined
ReferenceError: Packages is not defined

Why it happens

Rhino runs on the JVM, so some old snippets reached into Java classes (java.lang.System, java.util.UUID, Packages.…, JavaImporter). V8 is a pure JavaScript engine: there is no Java bridge.

Replacements

Rhino / Java	V8
`java.lang.System.currentTimeMillis()`	`Date.now()`
`java.util.UUID.randomUUID()`	`Utilities.getUuid()`
`java.lang.Thread.sleep(ms)`	`Utilities.sleep(ms)`
`java.net.URLEncoder.encode(s)`	`encodeURIComponent(s)`
Base64 / MD5 / SHA / HMAC	`Utilities.base64Encode`, `Utilities.computeDigest`, `Utilities.computeHmacSha256Signature`
Zip	`Utilities.zip` / `Utilities.unzip`
`new java.lang.String(s)`	just `s`
HTTP clients	`UrlFetchApp.fetch`

// Rhino
var id = String(java.util.UUID.randomUUID());
var t = java.lang.System.currentTimeMillis();

// V8
var id = Utilities.getUuid();
var t = Date.now();

How V8Shift handles it

Every java., javax., Packages.*, JavaImporter, importPackage and importClass is listed as a manual error with the suggested replacement.