Adding single user layout for ResolverActivity

This change adds an option for the callers of
ResolverActivity to start Resolver Sheet in single
user mode.
When not specified, Resolver Sheet is launched in
multi-user mode.

Test: Manual flash
Bug: 325576602
Change-Id: If97d91cf093efc78602bc8d2fdeadc8d43ddf73a
3 files changed