Remove the recommendation request impl and test code.

Removing most of the platform side request recommendation code and
its tests.

Test: adb shell am instrument -e class android.net.NetworkRecommendationProviderTest -w com.android.frameworks.coretests/android.support.test.runner.AndroidJUnitRunner
Test: runtest frameworks-services -c com.android.server.NetworkScoreServiceTest
Bug: 37357264
Change-Id: I36e592c5c82c38aa2174a51cf02c6e9825ef4f11
7 files changed