[SB][Chip] Update SBModeRepoImplTest for ChipsModernization flag.

Disabled ChipsModernization in the existing tests and added new tests
for when ChipsModerniztion is enabled.

Bug: 372657935
Flag: com.android.systemui.status_bar_chips_modernization
Test: atest StatusBarModeRepositoryImplTest
Change-Id: I317d76f3cfd38e6f471b28a48e55d4391c164ad7