Fix FeatureFlagsClassicDebugTest when multi user flag enabled.

Need to avoid recreating the mocked context object so that verifications
can run.

Bug: 355231569
Bug: 345443431
Test: atest -c com.android.systemui.flags.FeatureFlagsClassicDebugTest
Flag: com.android.systemui.classic_flags_multi_user
Change-Id: I4116a487b9a5134c8af699dc118480a698ff497b
1 file changed