Dynamically calculate network score.

To prepare for test before break for CBRS, we need to assign
different scores based on its network request it's serving.

Bug: 118348832
Test: manual
Merged-In: I5dec8d299602479d37e55a8e22344cdcd37e4341
Change-Id: I5dec8d299602479d37e55a8e22344cdcd37e4341
(cherry picked from commit 0b3da149)