Turn off the open hub complication on the dream

This is a quick CL to turn off the button as it's no longer wanted.
Will remove it more cleanly in a follow-up

Bug: 339667383
Test: manually verified on device
Flag: com.android.systemui.glanceable_hub_shortcut_button
Change-Id: I1d2938881a7c39c3d3d6dfe747dfd6737fba8f5e