Do i need police clearance certificate for all countries i have lived for H1B and green card applications to US?

Hi , i am an India passport holder and citizen.i am planning for H1B visa through my employer .Also i have been to Australia,UAE and Singapore.Do i need police clearance certificate from Australia,UAE and Singapore for the H1B visa ?

Not required to get these.

does the police clearance needed for the green card application?
because my friend has been asked to submit police clearance from all the countries he has lived. why is it so? now he is facing difficulty and time delay in getting the police clearance from all the countries he has lived…weird…

That is usually not the norm, but may have been case specific based upon name, past travel history etc.