Add ResetPasswordWithToken migration code.

Flag: android.app.admin.flags.reset_password_with_token_coexistence
Change-Id: Ibbd3c15d884d20aacc8a007f1ad7721c9d42ca47
Test: Manually tested. Generated a password token through TestDPC, enabled respective flag and rebooted. While rebooting, I've checked that the migration code was executed through logcat. After rebooting, I've successfully created a password with pre-existing token. After rebooting once more, I've checked that it didn't try to migrate again through logs.
Bug: 359187209