Several secure album changes.

- Make the lock screen photo be a standard portrait size photo
- In the filmstrip, have the first tap on the lock screen photo
  take the user directly to the unlock screen.
- Switch the asset to be a "locked" lock rather than an
  "unlocked" lock.

bug:7192331

Change-Id: If7541cd67cdfb711f8dd721796db3343ae91343a