[Bug]: Creating new shares doesn't use default admin sharing permissions

[skjnldsv]

Bug description

Since Nextcloud 27, when you create a new share, the FULL permissions 31 gets used, unless you specifically changes the custom permissions (which then, the default are also NOT used in the pre-checked checkboxes)

Steps to reproduce

1. Changes default permissions in admin settings
   
2. Create a user share
   

Expected behavior

The new share is created with the default permissions and not 31

Additional infos

Issue seems to come from the default permissions set being used here:

server/apps/files_sharing/src/views/SharingDetailsTab.vue

Lines 755 to 762 in e35f6d8

	if (this.isNewShare) {
	if (this.isPublicShare) {
	this.sharingPermission = BUNDLED_PERMISSIONS.READ_ONLY.toString()
	} else {
	this.sharingPermission = BUNDLED_PERMISSIONS.ALL.toString()
	}
	} else {

Historically, we used to sen the permissions as null to the Share OCS API and the backend would use the default permissions. Now it's always sent as 31 when untouched by the user.

[szaimen]

cc @Fenn-CS