Can I prevent auto-update of apps with changed permissions? I would like to auto-update any app that has no change in permissions.  Apps with changed permissions, I would like to review the changes before updating.  Is this possible?
You can choose do not auto update from the setting of play store 
when you open Play Store > My Apps (from NAVIGATION Drawer) if there will be any notification to update apps .. 
when you choose UPDATE / UPDATE all then it will ask for accept permissions if there is any change in permissions 

Well it is not possible but If you want to stop Auto-update apps on android then this might be the perfect answer
 1. Open PLAY STORE
 2. Play Store Setting
 3. TAP AUTO-update apps
 4. Choose From Options