fix: reset message batch limit to 500

Author: jonathanedey

firebase_admin/messaging.py

@@ -492,7 +492,7 @@ def send_each(self, messages, dry_run=False):
         """Sends the given messages to FCM via the FCM v1 API."""
         if not isinstance(messages, list):
             raise ValueError('messages must be a list of messaging.Message instances.')
-        if len(messages) > 1000:
+        if len(messages) > 500:
             raise ValueError('messages must not contain more than 500 elements.')
 
         def send_data(data):
@@ -521,7 +521,7 @@ async def send_each_async(self, messages: List[Message], dry_run: bool = True) -
         """Sends the given messages to FCM via the FCM v1 API."""
         if not isinstance(messages, list):
             raise ValueError('messages must be a list of messaging.Message instances.')
-        if len(messages) > 1000:
+        if len(messages) > 500:
             raise ValueError('messages must not contain more than 500 elements.')
 
         async def send_data(data):