Dump isPrimaryUser() / isSplitSystemUser() on 'user' service.

Also fixed / improved some javadocs...

Bug: 133242016
Test: manual verification

Merged-In: Ia9c50a2cd1de5ad8b0c9d5573b1760601fbcef76
Change-Id: Ia9c50a2cd1de5ad8b0c9d5573b1760601fbcef76
(cherry picked from commit d7b88384fe15dae2e70a2245d460b98be3b487eb)
2 files changed