Previously many usages of UserManager.getProfiles and getEnabledProfiles
were only using ids of returned users. Given that the list of users needs
to be parceled and unparceled for Binder calls, returning array of ids
minimizes memory usage and serialization time.
A new method getProfileIds was introduced which returns an array of userIds.
Existing method calls were updated where appropriate.
Bug: 27705805
Change-Id: Ib042f38d53d95d3b07cda7f824e5cb8c06cd10f5
4a4af5aec8