Add first impression type suggestion framework support

- category definition now supports "exclusiveExpireDays" attribute.
	- When set, the category is exclusive as long as it hasn't expired.
	  Once it expires, the category becomes a regular category.
	- If not set, the category is permanently exclusive
- For exclusive category, do not use smart suggestion dismiss rules.
  Instead, use the rule defined by suggestion itself.
- Add logic to ensure suggestions are unique, because there is nothing
  stopping suggestion to be placed in different categories.

Bug: 37947647
Test: make RunSettingsLibRoboTests -j40

Change-Id: I98126bbce6d68fcf1d739b6defc00b801075b877