Add a SettingsProvider key for Adaptive connectivity

Adaptive connectivity is a feature to manage 5G connectivity
for better battery life.

Bug: 162871294
Test: compile
Change-Id: I719e44a29a54ee886e5d3a7180fd3ad9a7dff599
Merged-In: I719e44a29a54ee886e5d3a7180fd3ad9a7dff599