Guard against app info crash

Change-Id: Ifb52ec61718723202e5ec7da5f9723a4764968ba
Fixes: 28171829
diff --git a/src/com/android/settings/applications/InstalledAppDetails.java b/src/com/android/settings/applications/InstalledAppDetails.java
index 7813745..808acbd 100755
--- a/src/com/android/settings/applications/InstalledAppDetails.java
+++ b/src/com/android/settings/applications/InstalledAppDetails.java
@@ -52,7 +52,6 @@
 import android.os.UserHandle;
 import android.os.UserManager;
 import android.provider.Settings;
-import android.service.notification.NotificationListenerService;
 import android.service.notification.NotificationListenerService.Ranking;
 import android.support.v7.preference.Preference;
 import android.support.v7.preference.Preference.OnPreferenceClickListener;
@@ -929,7 +928,7 @@
     }
 
     private boolean hasPermission(String permission) {
-        if (mPackageInfo.requestedPermissions == null) {
+        if (mPackageInfo == null || mPackageInfo.requestedPermissions == null) {
             return false;
         }
         for (int i = 0; i < mPackageInfo.requestedPermissions.length; i++) {