Check appEntry is not null before dereferencing it

Bug: 183791632
Test: make

Change-Id: Ic731f40031dca806428ffe85d6f2d10465ce7dea

packages/SystemUI/src/com/android/systemui/toast/SystemUIToast.java

@@ -233,7 +233,7 @@ public class SystemUIToast implements ToastPlugin.Toast {
             return null;
         }
         final AppEntry appEntry = appState.getEntry(packageName, userId);
-        if (appEntry.info == null
+        if (appEntry == null || appEntry.info == null
                 || !ApplicationsState.FILTER_DOWNLOADED_AND_LAUNCHER.filterApp(appEntry)) {
             return null;
         }