Well, it's pretty easy, just put your database.db in assets folder and you can use Android SQLiteAssetHelper to read and write the database, this library makes the process pretty easy and straightforward.
Import the library
compile 'com.readystatesoftware.sqliteasset:sqliteassethelper:+'
and then
public class MyDatabase extends SQLiteAssetHelper {
private static final String DATABASE_NAME = "northwind.db";
private static final int DATABASE_VERSION = 1;
public MyDatabase(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
That's all you need to do to access the database.
Here is the full example for your convenience.