Ensuring that ShortcutInfo always has an icon

> Making iconBitmap public instead of a getter (similar to AppInfo)
> Removing getIcon() which can lead to IO on UI thread
> Removing updateIcon and handling the update at the caller

Bug: 21325319
Change-Id: I6a49b9043f974e9629ea25e77012d97cc04c0594
17 files changed