Add the tethering type to TetheringEventCallback methods

Before this change, tethering always report a list of tethered
interfaces and the caller need to use each tethering type's interface
regex to matching tethered list to manual implement the mapping of
tethering type and interface. This change allow caller to get rid of
tethering interface regex.

Bug: 162920185
Bug: 152203943
Test: atest CtsTetheringTest on S
Ignore-AOSP-First: Currently aosp would automerge to mainlne-prod, merge
to sc-dev first to avoid adding new API to mainline-prod

CTS-Coverage-Bug: I already add cts test(ag/14622456), but Lint
still complaint because my cts is under packages/modules/Connectivity/
but it only check whether CL touching platform/cts
Change-Id: I91bcccd676d109c1b974497ac29bd366a41b8899