avrcp: Fix error creating media items

avrcp: Fix error creating media items

Don't use item name in the object path since it would need to be
properly escaped if the remote stack uses UID 0 even though it is
invalid to have 0 as UID:

AVRCP 1.6.1, page 84:

  'The value of UID=0x0 is a special value used only to request
   the metadata for the currently playing media using the
   GetElementAttributes command and shall not be used for any item
   in a folder.'

Change-Id: Id31a0ed0ebab207b5552466a051f1b9161d7b76b
Signed-off-by: himanshu <h.himanshu@samsung.com>