[Testing] To migration NetworkScorerPickerPreferenceControllerTest

1. Use AndroidJunit4 instead of RobolectricTestRunner
2. Use ApplicationProvider instead of RuntimeEnvironment to get context
3. Change Copy Right
4. Add a function which loads the Settings Resource.

Diff: https://diff.googleplex.com/#key=81Ufa1AWkLAi
Bug: 172047348
Test: atest -c NetworkScorerPickerPreferenceControllerTest
Change-Id: I9c1a4f957b92ab572eadbd8a0804bdc83608230b