Use getAllInterfaceNames to get all interface names

The current design is using hidden API - getStackedLinks() to
get LinkProperties then call getInterfaceName() to get the
interface name. In fact, this behavior could be replaced by
system API - getAllInterfaceNames().

Bug: 182963397
Test: atest FrameworksNetTests
Test: atest CtsNetTestCases
Change-Id: Id2b19dc5099355af69d23a6d99d2b7e6c0e1e88a