Add a method to create a TAP interface with a given interface name.

Add a method that allows the caller to specify whether to create a
tap interface with a given specific interface name instead of the
default one. So far only the given name that starts with "v4-testtap"
or "v4-testtun" prefix is allowed. That's helpful to create a clat
interface which always has "v4-" clat prefix in the IpClient integration
test, to verify the callbacks happend on adding/removing clat interface.

Bug: 163492391
Test: atest CtsNetTestCases
Change-Id: I9ea7013fce919cafb719998a123164b5507f9ac0
3 files changed