Use module resources in NetworkNotificationManager.

Also make getTransportName non-static so it can access the module
resources.

Also fix a duplicate comment in a resource file.

Bug: 183097033
Test: atest FrameworksNetTests
Test: connected to Wi-Fi with no Internet, observed notification
Change-Id: Ic0d24d36af0b87153d527083f8964ddc6cd78482
Merged-In: Ic0d24d36af0b87153d527083f8964ddc6cd78482