Updating network preference comments

Updating comments for network preferences to better clarify that
preferences which include more than one network type will then rely on
scoring to determine which of those networks are chosen.

Bug: 171795464
Test: atest FrameworksNetTests
Change-Id: I9eb5683f2cd69281bbee9fb70028d45f07720914
1 file changed
tree: ef1ba970a5ad7a4fda58bb552426b1f60076fe6d
  1. core/
  2. services/
  3. tests/