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