Fix WiFi icon in shade header being too large on connected displays

When connecting a display to a device, and pulling down the shade on
the connected display, the WiFi icon was much larger than the other
icons.

Since the shade moves between displays, there is a configuration change
when this move happens.
ModernStatusBarWifiView was not reacting to this configuration change to
update its dimensions.

Test: Connect a display and pull down shade
Test: ModernStatusBarWifiViewTest
Bug: 412409667
Flag: com.android.systemui.shared.status_bar_connected_displays
Change-Id: I03938e391933939d558c05eb1c8ea13ab1f8beb3