Protect against crash in fragment startup race

Because fragments can be hard.

Change-Id: I1eec2caf3729beaac2d36a97ba7cff422e546f44
Fixes: 32881893
Test: Look at device, verify no sysui crash dialog
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelView.java b/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelView.java
index 69d76e5..068631d 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelView.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelView.java
@@ -1226,7 +1226,7 @@
     }
 
     private String getKeyguardOrLockScreenString() {
-        if (mQs.isCustomizing()) {
+        if (mQs != null && mQs.isCustomizing()) {
             return getContext().getString(R.string.accessibility_desc_quick_settings_edit);
         } else if (mStatusBarState == StatusBarState.KEYGUARD) {
             return getContext().getString(R.string.accessibility_desc_lock_screen);