Adapt clickShortcutSettingsPreference* test to shortcut edit activity.

This failure appeared when rolling out flag
cleanup_accessibility_warning_dialog. This test used to always launch
the editor dialog, but that logic has changed with the rollout of
another feature to replace the dialog with an activity launch.

Bug: 319497827
Test: ToggleAccessibilityServicePreferenceFragmentTest
Change-Id: Ie4e3ae5eff8ed16cded622ce71bbd3a6a55cdedb