ShortcutManager: Address API review feedback.

- "delete" -> "remove"
- add/deleteDynamicShortcut() now takes a list.
- Throttling default settings is now 2 calls / hour.

- Add categories to ShortcutInfo.
- getIconResourceId() is now public

Bug 27923857
Bug 27548047

Change-Id: I8457b30e4b2f7c63ab2988648b37178fd16ea45b
11 files changed