Gallery2: Grant permission to read/write files of Settings.

Set photo of "user" via statusbar->more settings fails, because
that Gallery2 does not have the permission to read and write
files of Settings.

Grant read and write Settings permission to Gallery2.

Change-Id: Ifcc5b4d8d938960296c4fa9d0f7f302d353c3197
CRs-Fixed: 785671