[MM-42022] Don't break importing process on missing display name of a channel (#19641)

* Don't break importing process on missing display name of a channel

* remove unused strings

Co-authored-by: = <=>

app/import_validators_test.go

@@ -404,11 +404,13 @@ func TestImportValidateChannelImportData(t *testing.T) {
 		Type: &chanTypeOpen,
 	}
 	err = validateChannelImportData(&data)
-	require.NotNil(t, err, "Should have failed due to missing display_name.")
+	require.Nil(t, err, "Should have accepted having an empty display_name.")
+	require.Equal(t, data.Name, data.DisplayName, "Name and DisplayName should be the same if DisplayName is missing")
 
 	data.DisplayName = ptrStr("")
 	err = validateChannelImportData(&data)
-	require.NotNil(t, err, "Should have failed due to empty display_name.")
+	require.Nil(t, err, "Should have accepted having an empty display_name.")
+	require.Equal(t, data.Name, data.DisplayName, "Name and DisplayName should be the same if DisplayName is missing")
 
 	data.DisplayName = ptrStr(strings.Repeat("abcdefghij", 7))
 	err = validateChannelImportData(&data)