Add host side test for secondary user rollback

Run RollbackTest#testBasic only under a secondary user.

The host-driven test adds a new user and then installs the TEST (not the
test app) for that new user.
Note: this was the missing step in the previous attempt to test
RollbackTest under a secondary user.

Test: atest SecondaryUserRollbackTest
Test: test failed when multiuser support was removed from rollback
manager
Test: adb shell pm list packages --user 11 | grep rollback while running
the test in order to make sure the test is installing packages for the right user

Bug: 133852817
Bug: 129747710
Change-Id: I9e13f2cdaf825a53846765fa52bc425045f41df1
Merged-In: Id1e54769cc2a9631d1464c07bad2b685f78689bc