DB2 connector get exception possibly caused by setTransactionIsolation(0) [DBZ-9547]

Migrated from [DBZ-9547](https://issues.redhat.com/browse/DBZ-9547)

In order to make your issue reports as actionable as possible, please provide the following information, depending on the issue type.
h1. Bug report

For bug reports, provide this information, please:
h2. What Debezium connector do you use and what version?

v3.2.0.Final
h2. What is the connector configuration?

 
{
  "name": "db2-connector",  
  "config": {
    "connector.class": "io.debezium.connector.db2.Db2Connector", 
    "database.hostname": "db2", 
    "database.port": "5001",
    "database.user": "db2inst1", 
    "database.password": "123456", 
    "database.dbname": "testdb",
    "topic.prefix": "employee", 
    "table.include.list": "DB2INST1.EMPLOYEE_SALARY", 
    "schema.history.internal.kafka.bootstrap.servers": "kafka:9092", 
    "schema.history.internal.kafka.topic": "schemahistory.employee" 
  }
}
h2. What is the captured database version and mode of deployment?

(E.g. on-premises, with a specific cloud provider, etc.)

DB2 v10.5
h2. What behavior do you expect?

create connector successfully.
h2. What behavior do you see?

 there has an exception when I create a new connector on db2: "Invalid parameter: 0 is an invalid transaction isolation level.  See Javadoc specification for a list of valid values. ERRORCODE=-4461, SQLSTATE=42815". I just checked the source code and found the root cause may be in src\main\java\io\debezium\connector\db2\Db2SnapshotChangeEventSource.java method close(SnapshotContext snapshotContext), in this method it will call jdbcConnection.connection().setTransactionIsolation(0), and in db2 the 0 value should be not supported(TRANSACTION_NONE), only Connection.TRANSACTION_READ_UNCOMMITTED, TRANSACTION_READ_COMMITTED, TRANSACTION_REPEATABLE_READ, TRANSACTION_SERIALIZABLE were supported in db2
h2. Do you see the same behaviour using the latest released Debezium version?

(Ideally, also verify with latest Alpha/Beta/CR version)

yes
h2. Do you have the connector logs, ideally from start till finish?

(You might be asked later to provide [DEBUG/TRACE|https://debezium.io/documentation/reference/stable/operations/logging.html] level log)

[https://debezium.zulipchat.com/user_uploads/38476/Ggqbm5lPLCmjjxeUPTrbSUpE/PastedText.txt]

 
h2. How to reproduce the issue using our [tutorial|https://github.com/debezium/debezium-examples/tree/main/tutorial] deployment?

can setup a db2 database, open the ASN mode and try to create a new connector
h1. Feature request or enhancement

For feature requests or enhancements, provide this information, please:

The Db2SnapshotContext.class was defined with 
isolationLevelBeforeStart as 0 for default, maybe give another valid value should be better.
h2. Which use case/requirement will be addressed by the proposed feature?

h2. Implementation ideas (optional)