Don't display extra A2DP profile icon for OPP.

The getDrawableResource() method for OppProfileManager was returning
the resource ID for the A2DP icon. This was causing an extra headset
icon to be drawn for devices supporting OPP, when no icon should be
shown for this profile. Changed to return 0.

Bug: 3368197
Change-Id: Idcadaf59fe53301544cda215ca24f15608b2d727