Moved isCallerActiveScorer() to the score service.

Implemented isCallerActiveScorer() in the NetworkScoreService to make
it more efficient (no need to query PM). Exposed the call as a new
internal API on NetworkScoreManager and deprecated the call on
NetworkScorerAppManager.

Test: runtest frameworks-services -c com.android.server.NetworkScoreServiceTest
Bug: 33781558
Change-Id: I8ad232f8ef34b6e2f155ebb232e64300303300f0
Merged-In: I0e2142af95b068d322343f7c9362ac53d46b545e