fix: standardize notification defaults to false

Changes default values for email and push notifications to false
in LibresignActivitySettings, ensuring all LibreSign activity types
follow the same pattern and respect user opt-in preference.

Signed-off-by: Vitor Mattos <1079143+vitormattos@users.noreply.github.com>

Author: vitormattos

lib/Activity/Settings/LibresignActivitySettings.php

@@ -54,13 +54,13 @@ public function canChangeMail() {
 	 */
 	#[\Override]
 	public function isDefaultEnabledMail() {
-		return true;
+		return false;
 	}
 	/**
 	 * {@inheritdoc}
 	 */
 	#[\Override]
 	public function isDefaultEnabledNotification(): bool {
-		return true;
+		return false;
 	}
 }