WallpaperCropper: Fix crash when set .gif as wallpaper

It returns an equivalent scaled cropBounds as true
crop bounds, then it set the rounded rect by rounding
"out" the true crop rect, this make the rounded crop
rect may out range of the original bitmap, then an error
will happen.

We change to check the rounded crop rect, if it is out
the range of original bitmap, we set the original bitmap
bounds as rounded crop bounds.

CRs-Fixed: 622582

Change-Id: I215ef2a0165adaaadb05c62dee741a8ea6926144
wallpapercropper: OOM issue while opening *.bmp image

This change manages setting of large images as
wallpapers without encountering OOM.

CRs-fixed: 619815
Change-Id: I3a32ec4b42050b146076f0adf6b6e65afd6fae4e
Add wallpaper pickers to seperate package

Currently wallpaper pickers were part of the various launchers
and we were relying on Trebuchet's to add code for including
wallpapers from themes.  If Trebuchet is removed then this
functionality is lost.  This package is already included in all
builds so making the picker available here removes the dependency
on a specific launcher.

Trebuchet still contains a picker which should probably be removed
and make use of this package instead.

Change-Id: Ie42ae0e01f951a8293d13d6c8a73fde0dea6682b
WallpaperPicker: Destroy cropview to avoid leaks

If the cropview's TiledImageRenderer is rendering threads, the activity
context gets leaked. Avoid that by invoking its destroy in onDestroy() of activity.

Change-Id: I0804c903d14d3f3d13529f0fe90d12784d97e93f