Clean up flag notification_async_hybrid_view_inflation 5

The impact of this flag is particularly wide, so breaking down the flag
removal by method for code robustness and easier review. This change
cleans up the flag itself. By this step, there should be no usages of
the flag across the project anymore.

Clean up flag:
com.android.systemui.notification_async_hybrid_view_inflation

Fix: 409612328
Test: SingleLineViewInflaterTest, SingleLineViewBinderTest,
NotifUiAdjustmentProviderTest
Flag: EXEMPT flag cleanup

Change-Id: I26d870e50d811bceafbc5eff8d5aa7739aaf4967