[bugfix][dbus] Fix enabling issues with an active wifi connection

Maadajävri tries to auto connect more aggressively, which
interferes with the enabling process. So in case of an active wifi
connection, we'll first disconnect and power off wifi. Afterwards
we'll enable wifi tethering swiftly after powering on. And during
bluetooth tethering we'll leave wifi powered off.
[feature][dbus] Watch for cellular service auto connect changes
[bugfix][dbus] Disconnect packet data first on exit
[tethering] v0.2.7
[tethering] v0.2.7 release rpm