Merge changes from topics "enable-policy-ranking", "sendNetworkScore"

* changes:
  Adjust a test for policy scoring
  Enable policy ranking
  Add CTS to verify NetworkAgent#setLingerDuration
  Allow network providers to set the linger duration.
  Fix nascent timer never get removed
  [NS13] Remove the last usage of the legacy int
  Add documentation
  Use filter from CollectionUtils.
  Fix a bug where updates of offers won't find existing offers
  [NS12] Address comments on NS09
  [NS11] Fix yieldToBadWifi over the policy scoring
  Add doc for NetworkScore#getLegacyInt
  Expose sendNetworkScore that takes a NetworkScore