No. Wealth is only created in a mutually beneficial action. Otherwise it is simply transferred. By your logic, I could force you to give me your wallet and claim I’ve created wealth. As Paul points out above, if you enslave a population you have not created wealth, even if you force them to do something productive. You have merely taken wealth from them. Obviously, the population in your description preferred to eat fruits from the trees and sleep all day long. You even stated so yourself. Just because you force them to do something that you think is more valuable doesn’t mean they are richer for it. Obviously, if that population valued electricity and products from factories, they would have already chosen to do that work themselves. The fact that you have to force them to do it proves you are not creating wealth. You are stealing it.
Just ask the enslaved person if he feels he is better off after you came along than before, when he could sleep all day like he wanted. Just because you, the slave-driver, can say you’re better off doesn’t mean the slave is. In fact, he will tell you he is worse off. (Again, if he felt he was better off doing what you’re making him do, you wouldn’t have to force him to do it. He would do it voluntarily.) This unequivocally proves you have not created wealth. You have merely stolen it. You are better off because someone else is worse off…you have benefitted at the expense of someone else…you have gained, because someone else has lost. Wealth has not been created in your slave scenario. It has merely been transferred.