Incremented buffer size to accomodate default MTU

L2CAP Config request was not sent from Bluedroid as the MTU size was
higher than the max buffer size for default apdu tx/rx sizes.
Incremented the buffer size to accomodate this default MTU size. Also
included new datatypes and corresponding tx/rx apdus. This will set the
MTU size to that defined in datatype config rather than selecting
default value.
b/10565872
Change-Id: Id469c836581fb3d020bcb88c381421e0ef965073