Leave more buffer for state change between TOP & other state

When process has the activities with visible adn set to finish, the
state switch from TOP to IMFP may take more than 400ms, so give more
buffer for state to switch.

Test:run cts-on-gsi -m CtsIncidentHostTestCases -t com.android.server.
cts.BatteryStatsValidationTest#testUidForegroundDuration --skip-precond
itions

Bug: 112684940

Change-Id: Ie2f346ab9762b2acaddbcaaeab95708197815061
1 file changed