MM-27909: Add manage_shared_channels permission (#15601)

* MM-27909: Add manage_shared_channels permission

We add a new permission to manage shared channels.

It's a channel scoped permission and only the system admin
has that by default.

https://mattermost.atlassian.net/browse/MM-27909

* change to system scoped

* Trigger CI

* Trigger CI

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

app/app_test.go

@@ -180,6 +180,7 @@ func TestDoAdvancedPermissionsMigration(t *testing.T) {
 		},
 		"system_admin": allPermissionIDs,
 	}
+	assert.Contains(t, allPermissionIDs, model.PERMISSION_MANAGE_SHARED_CHANNELS.Id, "manage_shared_channels permission not found")
 
 	// Check the migration matches what's expected.
 	for name, permissions := range expected1 {

app/permissions_migrations.go

@@ -69,6 +69,7 @@ const (
 	PERMISSION_READ_PUBLIC_CHANNEL_GROUPS        = "read_public_channel_groups"
 	PERMISSION_READ_PRIVATE_CHANNEL_GROUPS       = "read_private_channel_groups"
 	PERMISSION_EDIT_BRAND                        = "edit_brand"
+	PERMISSION_MANAGE_SHARED_CHANNELS            = "manage_shared_channels"
 )
 
 func isRole(roleName string) func(*model.Role, map[string]map[string]bool) bool {
@@ -501,6 +502,15 @@ func (a *App) getAddConvertChannelPermissionsMigration() (permissionsMap, error)
 	}, nil
 }
 
+func (a *App) getAddManageSharedChannelsPermissionsMigration() (permissionsMap, error) {
+	return permissionsMap{
+		permissionTransformation{
+			On:  isRole(model.SYSTEM_ADMIN_ROLE_ID),
+			Add: []string{PERMISSION_MANAGE_SHARED_CHANNELS},
+		},
+	}, nil
+}
+
 // DoPermissionsMigrations execute all the permissions migrations need by the current version.
 func (a *App) DoPermissionsMigrations() error {
 	PermissionsMigrations := []struct {
@@ -520,6 +530,7 @@ func (a *App) DoPermissionsMigrations() error {
 		{Key: model.MIGRATION_KEY_ADD_USE_GROUP_MENTIONS_PERMISSION, Migration: a.getAddUseGroupMentionsPermissionMigration},
 		{Key: model.MIGRATION_KEY_ADD_SYSTEM_CONSOLE_PERMISSIONS, Migration: a.getAddSystemConsolePermissionsMigration},
 		{Key: model.MIGRATION_KEY_ADD_CONVERT_CHANNEL_PERMISSIONS, Migration: a.getAddConvertChannelPermissionsMigration},
+		{Key: model.MIGRATION_KEY_ADD_MANAGE_SHARED_CHANNEL_PERMISSIONS, Migration: a.getAddManageSharedChannelsPermissionsMigration},
 	}
 
 	for _, migration := range PermissionsMigrations {