Storage accessors; persist nickname, flags.

Move to using new public accessors on DiskInfo and VolumeInfo.

Persist nickname changes, and remember when user has initialized a
public volume.  Also skip the migration part of storage wizard until
it's implemented.

Bug: 19993667
Change-Id: I642fb43afb95380fddd48a1dad438e87b06454da

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

@@ -62,7 +62,7 @@ public class StorageWizardMigrateProgress extends StorageWizardBase {
             final Context context = StorageWizardMigrateProgress.this;
             if (e == null) {
                 final Intent intent = new Intent(context, StorageWizardReady.class);
-                intent.putExtra(DiskInfo.EXTRA_DISK_ID, mDisk.id);
+                intent.putExtra(DiskInfo.EXTRA_DISK_ID, mDisk.getId());
                 startActivity(intent);
                 finishAffinity();