Use shade dialog context when opening a PrivacyChip dialog

When the flag was on, the shade window context was being used, but it had the wrong window type and dialogs were failing to be created. Now the correct context associated with the shade is being used.

Bug: 362719719
Bug: 383294128
Test: PrivacyChipInteractorTest, HeaderPrivacyIconsControllerTest
Flag: com.android.systemui.shade_window_goes_around
Change-Id: Ief736b5c5d8352ae19adf77ba520e283f1713f7a