Flag Cleanup & class rename

Removes flag: com.android.systemui.use_notif_inflation_thread_for_footer
Removes flag: com.android.systemui.use_notif_inflation_thread_for_row
Renames RowAsyncLayoutInflater (a subclass of AsyncLayoutFactory) to RowAsyncLayoutFactory

Flag: EXEMPT removal
Test: presubmit
Fixes: 409605161
Fixes: 409607734
Change-Id: I8172f2f4c63bb7459c60746db442ba0fcdb574d0