Revert "Network stats: Hide if there's no traffic (1/2)"

This reverts commit d2f6ef3df7f28daf48572701f52fc1222a43b345.
Revert "NetStats: Don't update stats when screen is off"

This reverts commit 8df8560b3e28df85c9762a20f3cb6f352ef94d16.
Revert "Add network usage stats to status bar (1/2)"

This reverts commit 20d76ea21f3d6443726dee59d02a8a245cd6dfb7.