proguard: Keep SettingsActivity fragments

Change-Id: I26e12e11bc3fe63d05177562067dc5a41f86d33f
FontStylePreference: Initial preference with choice of font family

Change-Id: Idbb400605e47cd4f64a7edd05ceea05504727efc
Hotseat: Movable AllApps button

Change-Id: I4273c460392c8329368a23ef6f0d9698f52adfea
Workspace: Don't allow folder creation on AllApps icon

Change-Id: I5438ac81450450ba03c0f0cc6a33bd69dcbd0515