Rmove unuseful test for PackageMonitor change

In PackageMonitor, it is no longer based on broadcast receivers to
listen package added/removed/... events. Therefore the verification
should be removed.

Bug: 340387113
Test: atest SettingsRoboTests:com.android.settings.accessibility.AccessibilitySettingsTest
Change-Id: I7b0d46add06c74f1b9bf1097f92dececa9b130de