ColorDisplayService: Check for null content observer before unregistering

- Early user switching in car env can lead into NPE

Bug: 133857745
Test: boot in car env
Change-Id: I3d2f67f1a57fc1f7dabb43d4917bbe3d83492852

1 files changed, 3 insertions, 1 deletions

diff --git a/services/core/java/com/android/server/display/color/ColorDisplayService.java b/services/core/java/com/android/server/display/color/ColorDisplayService.java
index b2420b5b320e..64a9e0074cb1 100644
--- a/services/core/java/com/android/server/display/color/ColorDisplayService.java
+++ b/services/core/java/com/android/server/display/color/ColorDisplayService.java
@@ -394,7 +394,9 @@ public final class ColorDisplayService extends SystemService {
     private void tearDown() {
         Slog.d(TAG, "tearDown: currentUser=" + mCurrentUser);
 
-        getContext().getContentResolver().unregisterContentObserver(mContentObserver);
+        if (mContentObserver != null) {
+            getContext().getContentResolver().unregisterContentObserver(mContentObserver);
+        }
 
         if (mNightDisplayTintController.isAvailable(getContext())) {
             if (mNightDisplayAutoMode != null) {