Rename notificationSizeValidator to isNotificationSizeValid
Summary:
Rename notificationSizeValidator function to make it more obvious it returns true if size is valid.
Depends on D13712
Test Plan:
- Create chat
- Verify that notifications are still working
Reviewers: ashoat, kamil
Reviewed By: ashoat
Subscribers: ashoat, tomek
Differential Revision: https://phab.comm.dev/D13713