Add test configuration values for probe URLs

The test configuration values override RROs that may have been set by
OEMs, which is necessary to be able to rely on them in CTS tests.

Test: atest NetworkStackTests
Bug: 152280218
Merged-In: I8171fd6360a6e504f3abaea3d7de4fa308bbb35b
Change-Id: I8171fd6360a6e504f3abaea3d7de4fa308bbb35b
3 files changed