Add simple null checks to StorageWizard*, also listen to...

the disk destroyed event.

Bug 21336042

Change-Id: I9f53501a6122a4a9046774e3c4c08b5d6d6f8552

src/com/android/settings/deviceinfo/StorageWizardMoveConfirm.java

@@ -36,6 +36,10 @@ public class StorageWizardMoveConfirm extends StorageWizardBase {
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
+        if (mVolume == null) {
+            finish();
+            return;
+        }
         setContentView(R.layout.storage_wizard_generic);
 
         try {
@@ -45,9 +49,6 @@ public class StorageWizardMoveConfirm extends StorageWizardBase {
             throw new RuntimeException(e);
         }
 
-        Preconditions.checkNotNull(mVolume);
-        Preconditions.checkNotNull(mApp);
-
         // Sanity check that target volume is candidate
         Preconditions.checkState(
                 getPackageManager().getPackageCandidateVolumes(mApp).contains(mVolume));