chore: import upstream snapshot with attribution

modules/java/generator/templates/java_class.prolog

@@ -0,0 +1,20 @@
+//
+// This file is auto-generated. Please don't modify it!
+//
+package org.opencv.$module;
+
+$imports
+
+$docs$annotation
+public class $jname {
+
+    protected final long nativeObj;
+    protected $jname(long addr) {
+      nativeObj = addr;
+      $jcleaner
+    }
+
+    public long getNativeObjAddr() { return nativeObj; }
+
+    // internal usage only
+    public static $jname __fromPtr__(long addr) { return new $jname(addr); }