Remove explicit ViewCaptureAwareWindowManager usage in MagnificationModeSwitch window.

We change this due to the restructure of ViewCaptureAwareWindowManager  (go/wm-for-viewcapture)

Bug: 364461638
Flag: com.android.systemui.enable_view_capture_tracing
Test: tested locally

Change-Id: I6797ab9d5a9d0ff26d9ce999214e6040f01e3e95