Update VE core submodule to master (3feadb2)

New changes:
fc4af20 Fix filibuster expansion bug
3feadb2 [BREAKING CHANGE] Refactor for multiple surfaces

Local changes:
* Use target.getSurface now that targets can have multiple surfaces
* Remove debug bar code now surfaces manage their own
* Remove import rules code now implemented in base target

Change-Id: I18d6f9f2f36431959d31347b4c1952a1aca1350e
Merge "Update VE core submodule to master (3feadb2)"