Moving the setContentView at the end of onCreate

In multi-window mode, when the activity is resized, the window might
exist even before onCreate, which could call onAttachToWindow while
they are being inflated. Many Views in Launcher assume
onAttachToWindow to be called after onCreate has completed.

Bug: 32745705
Change-Id: Id6ee68826c4f3cc579880540812fd8ed834f8267