Damaged thumbnail shows on Photo Roll after delete photo.

[Hannah Zhu]

Information:
phablet@ubuntu-phablet:~$ system-image-cli -i
current build number: 413
device name: krillin
channel: ubuntu-touch/rc-proposed/bq-aquaris.en
last update: 2016-08-23 14:49:50
version version: 413
version ubuntu: 20160823
version device: 20160606-ab415b2
version custom: 20160805-985-38-15

Precondition:
DUT storage more than 30 photos on com.ubuntu.camera folder.

Step:
1. Launch the camera app
2. Slide left to launch Photo Roll
3. Switch to the thumbnail view (by press the list icon on the right top)
4. Long press one photo and select it by check the checkbox.
5. Select some photos more.
6. Delete these photos.
7. Scroll down the page and then scroll up back.
8. Check the thumbnail.

Actual result:
The deleted photo shows damaged thumbnail on Photo Roll.

Expect result:
The deleted photo shouldn't show on Photo Roll