Prevent NPE if View has not been initialized

Sets the list to always be non-null (start with a non empty list)

Test: manual (no NPE)
Fixes: 222722721
Change-Id: I1ef5241cca189a857f39a737ba73638b44ef9a60

packages/SystemUI/src/com/android/systemui/qs/QuickStatusBarHeader.java

@@ -102,7 +102,7 @@ public class QuickStatusBarHeader extends FrameLayout {
     private int mTopViewMeasureHeight;
 
     @NonNull
-    private List<String> mRssiIgnoredSlots;
+    private List<String> mRssiIgnoredSlots = List.of();
     private boolean mIsSingleCarrier;
 
     private boolean mHasCenterCutout;