Gallery2: Sign SIM card number for Mobile Data to Setting

When choose prefered APN in Streaming Settings, there is no default
SIM card number for mobile data, so the reset function is not available.

In the intent for APN setting, add the SIM card number for default
set.

CRs-Fixed: 731357

Change-Id: I30e9e361af504be851adef0537d7512150338783
Gallery2: Fix file exist in SD card when delete from Gallery

The permission of writing sd card is not effective which cause
this bug happen.

Add write sd card permission.

CRs-Fixed: 754706

Change-Id: Idd14a7ffbcce1e35d7ca6272118c48014758a1a5
Gallery2: don't pause background music perminently

Gallery app requests transient audio focus twice and explicitly pauses
background music playback. To allow music resume after movie playback
exists, remove redundant audio focus request and pause broadcast.

CRs-Fixed: 695669
Change-Id: I46b88defc887d3e5b5c97acdc4f5a0a11d486a76