Recreate icon factory to update default scale

Issue: icons are normalized correctly on first creation, but not on subsequent theme change.

This happens because Launcher manually updates the default adaptive icon scale, but SysUI does not.

This change recreates BubbleIconFactory (a stateless class) after theme change, to update the default adaptive icon scale used by IconNormalizer.

Bug: 129158983
Test: atest SystemUITests
Test: manual - icons normalize to same size after theme change
Change-Id: Ibc0b11b10e2585bbec18d4f8a4aa4acec43b5a6a