Fix role granting flow.

This change fixes various issues realted to the role granting
flow, including allowing permission controller to be granted
SET_PREFERRED_APPLICATIONS for roles, granting
MANAGE_ROLE_HOLDERS permission to shell, and improving
RoleUserState XML parsing.

Bug: 110557011
Test: build
Change-Id: Ia095580ad497af9cf7b29e6bedab70046b09d542