Windows has a "Read-only" property. If you right click on the files in "File Explorer" then on the "Properties" button a dialog will pop-up with a check box for the "Read-only" property at the bottom. If they are checked for those two files, uncheck the checkboxes, launch Android Studio and try the update again. If they are not checked, then I have shot my wad and it is a different problem, but it is odd that the same two files were a problem on my computer and they had their write permissions turned off, and turning on write permission was all that was needed. Hope this helps.