Revert^2 "Visit URIs in intents associated with notifications."

This reverts commit 5b584b43.

This was originally failing because it was merged around the same time
with ag/25599460, and disabling the MODES_API flag by default in the
@Before method using SetFlagsRule, only to then enable it using
@EnableFlag in a test did not work well.

Flag: ACONFIG android.app.VISIT_RISKY_URIS DEVELOPMENT
Bug: 281044385
Test: atest NotificationVisitUrisTest NotificationManagerServiceTest

Change-Id: I5395a29a53502e0c2b80b4986a657706aa340423