Don't crash when procstats has data for a now-disused uid

That is, PackageManager.getPackagesForUid(uid) can return null,
so deal with it.

Bug 10374656

Change-Id: I4eacd48c809b778e131d37dba0e86c583553e41f

src/com/android/settings/applications/ProcessStatsUi.java

@@ -335,6 +335,7 @@ public class ProcessStatsUi extends PreferenceFragment {
             }
             if (targetApp == null) {
                 String[] packages = pm.getPackagesForUid(proc.mUid);
+                if (packages != null) {
                     for (String curPkg : packages) {
                         try {
                             final PackageInfo pi = pm.getPackageInfo(curPkg,
@@ -356,6 +357,10 @@ public class ProcessStatsUi extends PreferenceFragment {
                         } catch (PackageManager.NameNotFoundException e) {
                         }
                     }
+                } else {
+                    // no current packages for this uid, typically because of uninstall
+                    Log.i(TAG, "No package for uid " + proc.mUid);
+                }
             }
             pref.setTitle(label);
             if (targetApp != null) {