OBEX: Implementation of MAP and PBAP client role on Bluedroid.

Implementation changes to support MAP client and PBAP client
role on Bluedroid stack.

Change-Id: Ic75e0bea10b8420aef928d868cc25acd769d5620
CRs-fixed: 530274
(cherry picked from commit 8a9036e632092e7311e5009cb96a016b52bbacca)
(cherry picked from commit 1e4719192c82f89d0b2dba67ec99c72c77060f9a)
(cherry picked from commit abb73fd0ef2dd64c44944cff99dc81c1fd368d36)