cmake: Java/Android SDK refactoring

modules/java/generator/templates/java_class.prolog

@@ -0,0 +1,15 @@
+//
+// 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; }
+
+    public long getNativeObjAddr() { return nativeObj; }