[Mac] [sys_config] Setting Touch Bar to show Fn keys first sets Fn keys to be media keys first on non-touchbar MacBooks

[rucker]

Issue observed on mid 2015 MBP. After making the relevant config changes, everything appears as though Fn keys should function as Fn keys first in Keyboard preferences (below). The issue can only be corrected by changing the value of "Press Fn key to" dropdown to another value, then back to "Do Nothing"