Fix NullPointerException in SmartAutoRotateCameraStateController

Test: none

Bug: 184844470
Change-Id: I9eca78b11ff8a70dc7c026d7ef77e0b08db8ffbe
diff --git a/src/com/android/settings/display/SmartAutoRotateCameraStateController.java b/src/com/android/settings/display/SmartAutoRotateCameraStateController.java
index 9e2a784..a17a903 100644
--- a/src/com/android/settings/display/SmartAutoRotateCameraStateController.java
+++ b/src/com/android/settings/display/SmartAutoRotateCameraStateController.java
@@ -44,7 +44,9 @@
         super(context, key);
         mPrivacyManager = SensorPrivacyManager.getInstance(context);
         mPrivacyManager.addSensorPrivacyListener(CAMERA, (sensor, enabled) -> {
-            mPreference.setVisible(enabled);
+            if (mPreference != null) {
+                mPreference.setVisible(enabled);
+            }
             updateState(mPreference);
         });
     }