Initial changes to support a fixed all-apps layout.

- Dynamically update padding and background depending on fixed bounds and searchbar
- Fixes issue with drag layer bg getting clobbered when rotating launcher
- Tapping outside the bounds of all apps should close all apps
- Fixing typo causing widgets to not show in sw720dp devices

Bug: 20127840

Change-Id: I29c3f905bdee940f938ffe054f58434887073092