Fix NullPointerException by 'adb shell service call uimode 1' am: a62ca14425 am: 7430988418 am: 649213e07b

Original change: https://android-review.googlesource.com/c/platform/packages/services/Telecomm/+/2026103

Change-Id: Ica5fb681dc96dfe06e8f7def5d73c0192d910045
diff --git a/src/com/android/server/telecom/InCallController.java b/src/com/android/server/telecom/InCallController.java
index e29d905..1e8f779 100644
--- a/src/com/android/server/telecom/InCallController.java
+++ b/src/com/android/server/telecom/InCallController.java
@@ -2166,6 +2166,10 @@
     public void handleCarModeChange(int priority, String packageName, boolean isCarMode) {
         Log.i(this, "handleCarModeChange: packageName=%s, priority=%d, isCarMode=%b",
                 packageName, priority, isCarMode);
+        if (packageName == null) {
+            Log.i(this, "handleCarModeChange: Got null packageName, ignoring");
+            return;
+        }
         // Don't ignore the signal if we are disabling car mode; package may be uninstalled.
         if (isCarMode && !isCarModeInCallService(packageName)) {
             Log.i(this, "handleCarModeChange: not a valid InCallService; packageName=%s",