Remove ambient status bar from Glanceable Hub.

This changelist removes the ambient status bar from Glanceable Hub in
favor of using the standard keyguard status bar.

Test: KeyguardStatusBarViewControllerTest
Fixes: 399687381
Flag: com.android.systemui.glanceable_hub_v2
Change-Id: I10ff51838b58b84c50093b947eaafd8f2bfbd00b