Turn down default dock icons number.
In low res devices and low dpis, 7 icons is too much and the icons collapse.

Change-Id: Ib4b2dc26f62dbd7ebe6dfdd8cb3c740687c2d84b
Fix derp setting default values

Change-Id: Ib0a88260ff299cc70ad6224b8c3c9f93301f2dea
Fix dock preferences default values

Change-Id: I37d52b7df9272ff4f7d3985e6df76f5edc5c6b64