RC: add switch to hide signal and wifi bars (2/2)

Change-Id: I2157547a91002e17a2475d517e17f55345fcfb34
Make pie being dependent on expanded desktop optional (2/2) - SlimBean

ps3: Fix system setting name
ps6: tweak default state

Change-Id: Ifd8d96dbcd61fdfa5528f37944cb7fd8f47700c8 (reverse-merged from commit 919fbdb32e47f1417109a5eb5282df09c355a2de)