Fix NPE in AppListPreference when there is no default.

Bug: 14327074
Change-Id: I3b0dcfbefcfb91278582457beef5823072efc46a
diff --git a/src/com/android/settings/AppListPreference.java b/src/com/android/settings/AppListPreference.java
index 919720f..2180983 100644
--- a/src/com/android/settings/AppListPreference.java
+++ b/src/com/android/settings/AppListPreference.java
@@ -94,7 +94,8 @@
             if (appInfo != null) {
                 applicationNames[index] = appInfo.loadLabel(pm);
                 mEntryDrawables[index] = appInfo.loadIcon(pm);
-                if (appInfo.packageName.contentEquals(defaultPackageName)) {
+                if (defaultPackageName != null &&
+                        appInfo.packageName.contentEquals(defaultPackageName)) {
                     selectedIndex = index;
                 }
                 index++;