Fix large clock is wrongly scaled down in lockscreen and wrong pivot when applying scale in AOD

That large clock is scaled down in lockscreen is because we apply scale from scaleViewModel when scaleClockOnly is true (large clock is visible) in AOD, but we didn't recover it when small clock is visible, so AOD scale value is kept in large clock views when transitioning from AOD to lockscreen. So when we change from small to large clock, we use the legacy scale value, which scale large clock down in lockscreen.

That wrong pivot issue is fixed by explicitly clear pivot whenever applyConstraints is called in ClockSection to avoid using legacy value when clone / applyTo is called for constraintSet.

Bug: 357182038
Test: mannually test by showing large clock with notification in landscape mode of Felix, and then fold the device and clear notification, see that the log outputs the correct value for scale and pivotX.
Flag: com.android.systemui.migrate_clocks_to_blueprint

Change-Id: I92a2befd48f257e93bf088af60cafe9e212eac6a