UserLifecycleTests: long max test run time

In order to stabilize the tests, additional waits (for the system to
cool down) were added in ag/15685704. On slower devices, that can make
the tests time out, so we must increase the timeout time.

It would have been nice to use org.junit.rules.Timeout instead, but that
doesn't seem to work; the test still times out after 5min that way.

Bug: 169449457
Bug: 198013452
Test: atest MultiUserPerfTests:android.multiuser.UserLifecycleTests with delays
Change-Id: Ia713121b2c52acd62d990b526e3d5aca2bb46b49