Add validation type definition to support multiple probe result

In order to allow NetworkMonitor to tell ConnectivityService
if the network is either parital, validated or both.
NetworkMonitor could update the probe result by passing the
bitmask to ConnectivityService.

Bug: 130078798
Bug: 130683832
Test: build
Change-Id: I429ccbd9b9afae3eafaf73b3c9eb835213c1f64d
Merged-In: I429ccbd9b9afae3eafaf73b3c9eb835213c1f64d
(cherry picked from commit 4932896e244be2edb028552e02374b41e3f7d365)