DBZ-7554 AvroConverter fails to parse events on tables with multiple …

…columns

Adjust schema names for cells to be unique. Avro uses these names to
identify sub schema declarations and will not redefine a sub schema that
was already detected. In this case, if we have cells with multiple
types, debezium will fail to serialize the event, since the stored avro
schema does not match the cells.

core/src/main/java/io/debezium/connector/cassandra/CassandraSchemaFactory.java

@@ -195,7 +195,7 @@ static Schema rowSchema(List<String> columnNames, List<DataType> columnsTypes) {
             for (int i = 0; i < columnNames.size(); i++) {
                 Schema valueSchema = CassandraTypeDeserializer.getSchemaBuilder(columnsTypes.get(i)).build();
                 String columnName = columnNames.get(i);
-                Schema optionalCellSchema = CellData.cellSchema(valueSchema, true);
+                Schema optionalCellSchema = CellData.cellSchema(columnName, valueSchema, true);
                 if (optionalCellSchema != null) {
                     schemaBuilder.field(columnName, optionalCellSchema);
                 }
@@ -296,13 +296,13 @@ public Struct record(Schema schema) {
             }
         }
 
-        static Schema cellSchema(Schema columnSchema, boolean optional) {
+        static Schema cellSchema(String columnName, Schema columnSchema, boolean optional) {
             if (columnSchema == null) {
                 return null;
             }
 
             SchemaBuilder schemaBuilder = SchemaBuilder.struct()
-                    .name(CELL_SCHEMA_NAME)
+                    .name(columnName)
                     .version(CELL_SCHEMA_VERSION)
                     .field(CELL_VALUE_KEY, columnSchema)
                     .field(CELL_DELETION_TS_KEY, OPTIONAL_INT64_SCHEMA)