Add TunnelInterface API and KernelResourceRecords

This change adds one KernelResourceRecord type (TunnelInterfaceRecord),
and adds methods for the creation of TunnelInterfaces, as well as the
application of Transforms to the given TunnelInterfaces

As part of the generation of ikeys/okeys, a ReserveKeyTracker manages a
java bitset to avoid collisions and reserve/release keys.

Bug: 63588681
Test: Compiles, CTS, unit tests all pass on AOSP_marlin
Change-Id: I9e9b6455e27073acd4491eae666aa966b3b10e0f
7 files changed