Use conf.d for the NetworkManager config

This moves the parts of the NetworkManager config that appear to be important
to a surface-specific file in conf.d. That way, no config is overwritten when
installing the files.

Signed-off-by: Dorian Stoll <dorian.stoll@tmsp.io>

root/etc/NetworkManager/NetworkManager.conf

@@ -1,12 +0,0 @@
-[main]
-plugins=ifupdown,keyfile,ofono
-#dns=dnsmasq
-
-[ifupdown]
-managed=false
-
-[connection]
-wifi.powersave = 2
-
-[device]
-wifi.scan-rand-mac-address=false

root/etc/NetworkManager/conf.d/99-surface.conf

@@ -0,0 +1,5 @@
+[connection]
+wifi.powersave = 2
+
+[device]
+wifi.scan-rand-mac-address=false

root/etc/NetworkManager/conf.d/default-wifi-powersave-on.conf

@@ -1,2 +0,0 @@
-[connection]
-wifi.powersave = 2