feat: make assets folder name configurable

# Feature Request

## Motivation Behind Feature

cordova-ios has a `wwwFolderName` to configure the name of the folder where the cordova app is loaded (defaults to www).
On Android the www is hardcoded in several places.

## Feature Description

note that on cordova-ios it's only configurable with code, so not meant to be changed from config.xml, is for when integrating cordova into native projects.

## Alternatives or Workarounds

Start by locating the Android code paths where the `www` folder is hardcoded, then compare them with cordova-ios's `wwwFolderName` behavior. The work is done when native integrations can configure the assets folder name in code, while the existing default behavior remains unchanged and config.xml is not required.

Written by the indexing model from the issue text.