Rename show_biometric_prompt_secondary_display_toast to trigger a new gantry workflow.

Its namespace was changed in ag/34937001 but that did not trigger a new gantry workflow

Bug: 419799860
Flag: com.android.window.flags.show_biometric_prompt_secondary_display_message
Change-Id: Ica9e7bb3c5b4d7f51ff32c273d6544e1b3cdca3a