MM-40817: Use license interface in Channels (#19678)

* MM-40817: Use license interface in Channels

https://mattermost.atlassian.net/browse/MM-40817

```release-note
NONE
```

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

api4/role.go

@@ -145,7 +145,7 @@ func patchRole(c *Context, w http.ResponseWriter, r *http.Request) {
 	}
 
 	isGuest := oldRole.Name == model.SystemGuestRoleId || oldRole.Name == model.TeamGuestRoleId || oldRole.Name == model.ChannelGuestRoleId
-	if c.App.Srv().License() == nil && patch.Permissions != nil {
+	if c.App.Channels().License() == nil && patch.Permissions != nil {
 		if isGuest {
 			c.Err = model.NewAppError("Api4.PatchRoles", "api.roles.patch_roles.license.error", nil, "", http.StatusNotImplemented)
 			return
@@ -173,7 +173,7 @@ func patchRole(c *Context, w http.ResponseWriter, r *http.Request) {
 		*patch.Permissions = model.RemoveDuplicateStrings(*patch.Permissions)
 	}
 
-	if c.App.Srv().License() != nil && isGuest && !*c.App.Srv().License().Features.GuestAccountsPermissions {
+	if c.App.Channels().License() != nil && isGuest && !*c.App.Channels().License().Features.GuestAccountsPermissions {
 		c.Err = model.NewAppError("Api4.PatchRoles", "api.roles.patch_roles.license.error", nil, "", http.StatusNotImplemented)
 		return
 	}