It depends on how do you deploy the menu.html
In case if you place it in bundle and use JS application it should be like this:
start_path = 'file://%APP_PATH%/public/menu.html'
In case if you use application with ruby controllers it should be like this:
start_path = ‘app/menu.html
In case you want to use old RE1.0/2.0 shared runtime style you need define shared_runtime capability at build.yml and use config.xml to define start path as in RE1.0 app
I have tried "%APP_PATH%" with html file placed in bundle, it works. Thank you very much!
Unfortunately I couldn't find "shared_runtime" capability option in build.yml, is it supported option for RMS 4.0?
I think it is best to get/look "shared runtime" application from rhoelements gem: <rhoelements>/RhoElements2/
It is not supported officially for Android in rhoelements 4.0 (and no prebuilt package is provided) but you should be able to build it yourself