Adjust toolbar/action bar title handling

Treat activity title changes as window title changes when propagating
to action bars. This gives it lower priority if a "hard" title has
been set. Fix some lifecycle handling around this that previously
resulted in multiple calls.

Automatically detect the starting display options for a
ToolbarWidgetWrapper if we're not grabbing them from styles. This
prevents setTitle and friends from going totally out to lunch if
constructed around a Toolbar with no starting title.

Bug 17138048

Change-Id: I9f58a3d222546745c8aa873e996b8f0d52a0ad21