Merge "Move TestableNetworkAgent to Common Util Location" am: eef1e2033d am: d71552978c am: 7bf5e7e325

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/1908520

Change-Id: I19e75581c18901eef23d4dd50ec62bbc6a8f66da