Themes: Don't recreate network controllers

When re-creating the network controllers we lose their current
state, which results in a bug on multi-sim devices where the first
sim slot will show the no connectivity icon rather than the no sim
icon when no sim is present.

Change-Id: I169734b1f5c7b17e11cc15a3434a22ed9f7bce1f
REF: TOMATOL-160
(cherry picked from commit 676a0c5d)