Revert permission check on setActiveScorer.

Reverted to the pre-O behavior of allowing the call if the caller
has the SCORE_NETWORKS permission.

Test: runtest frameworks-services -c com.android.server.NetworkScoreServiceTest
Bug: 37722313
Change-Id: I54a99dde364d6a5c88d35072922020542c6ae003
4 files changed