PBAP: Handle '-' in TEL field properly when custom TAG is used.

Precondition:
DUT has some contacts stored along with phonenumber(s) stored
with custom tag option.

Usecase:
1) Connect with carkit supporting PBAP
2) Send download phonebook from carkit

Expectation:
Carkit is able to show all phonebook contacts and numbers stored on DUT

Observation:
Carkit is unable to show some phonenumbers stored with custom tag option.

Issue:
For Contacts with custom Tel field, "-" is deleted from tag syntax.
Proper Format: X-TAG:<TEL_Number>
Received Format : XTAG:<TEL_Number>

Issue:
For Contacts with custom Tel field, "-" is deleted from tag syntax.
Proper Format: X-TAG:<TEL_Number>

Root Cause:
"-" is getting deleted from TEL number and "X-TAG" as well when
custom tag is used for contact.

Fix:
remove "-" only from TEL number without removing it from "X-TAG".

Test: Tested that carkit is able to show all contacts/numbers properly
stored even with custom fields.

Bug: 37712333
Change-Id: Id4cafa5de44e90a215c18053c872e9b40792eba3