mms: use InternalContactsCount instead of the non-public ContactsCount interface

requires: http://review.cyanogenmod.org/#/c/80954/

Change-Id: I0217d5309678f4e91ecf48be8378175369c03b05
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>
Merge branch 'remote' into mkl