JobScheduler: Fix ThermalStatusRestrictionTest failure

Test case need to be flagged due to ignoring of the
important while foreground flag.

Bug: 374175032
Bug: 376184833
Test: atest
FrameworksMockingServicesTests: com.android.server.job.restrictions.ThermalStatusRestrictionTest
Flag: EXEMPT bugfix
Change-Id: I4927edf60b6812b27e7a0fc806b2e7060877a0fe