I'm trying to identify a sci fi short story or novella set in a post-apocalyptic earth where humans are long gone. What remains on earth are just robots. I remember that the earth is divided in two territories. The leader of one territory develops a desire to become a human being. He visits remnants of museums and tries to do human activities like painting. Later, he realizes that he can only be human if he has a human body. He collects a number of mummified human bodies in the mountain and creates clones. The leader of the other territory orders him to stop because this is against the rules.
When the robot 'soldiers' sent to stop him arrives, he has already transferred his consciousness in a man's body. The robot soldiers recognize him at once as a man and it was revealed that robots are designed to obey humans. The story ends with him asking the other leader if it wants to be a woman.
I believe this was written by a popular author but I couldn't find it on the web. Thanks.