Improve NetworkMonitor testing for ConnectivityDiagnostics.

This change improves testing for changes made to NetworkMonitor for
passing data through to ConnectivityDiagnostics inside
ConnectivityService. Specifically, this test adds stronger assertions on
the contents of the PersistableBundles passed in
notifyNetworkTestedWithExtras and notifyDataStallSuspected.

This change also reorganizes how ArgumentMatchers are utilized in
verifying the contents of the PersistableBundles.

Bug: 147249364
Bug: 143187964
Test: atest NetworkStackTests
Change-Id: Iead78a102e26b43f1b7329166a83bf34a6a52b0f