[Dual Shade] Avoid showing the battery icon twice in QuickSettings shade

Fix: 414749885
Test: Manually tested by opening the single shade on a device without a
 center cutout, and observing that the battery estimate is shown instead
 of percentage.
Flag: com.android.systemui.scene_container
Change-Id: Icd69362a3636d8e504f1cb76354b708c644652c9