[AWS::RDS::DBParameterGroup] False-positive drift detection results

### Name of the resource

AWS::RDS::DBParameterGroup

### Resource Name

_No response_

### Issue Description

Freshly-provisioned [AWS::RDS::DBParameterGroup](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-rds-dbparametergroup.html) reports drift for [Parameters](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-rds-dbparametergroup.html#cfn-rds-dbparametergroup-parameters) property.

Peculiarly, it (so far) seems to only report false-positively for *shared_preload_libraries* and *track_activity_query_size* keys. Even more weirdly, only when *track_activity_query_size* == ```4096```

### Expected Behavior

Stack IN_SYNC

### Observed Behavior

*shared_preload_libraries* key missing from actual.
*track_activity_query_size* key missing from actual, but only when value is ```4096```!!

### Test Cases

```
parameter_group = rds.ParameterGroup(self, "ParameterGroup",
engine=rds.DatabaseInstanceEngine.postgres(
version=rds.PostgresEngineVersion.VER_14_2),
description='Testing drift',
parameters={
"shared_preload_libraries": "pg_stat_statements",
"track_activity_query_size": "4095"
}
)
```

**IN_SYNC**

Expected:
```
{
"Family": "postgres14",
"Description": "Testing drift",
"Parameters": {
"shared_preload_libraries": "pg_stat_statements",
"track_activity_query_size": "4095"
}
}
```

Actual:
```
{
"Family": "postgres14",
"Description": "Testing drift",
"Parameters": {
"track_activity_query_size": "4095"
}
}
```

---

```
parameter_group = rds.ParameterGroup(self, "ParameterGroup",
engine=rds.DatabaseInstanceEngine.postgres(
version=rds.PostgresEngineVersion.VER_14_2),
description='Testing drift',
parameters={
"shared_preload_libraries": "pg_stat_statements",
"track_activity_query_size": "4096"
}
)
```

**DRIFTED**

Expected:
```
{
"Family": "postgres14",
"Description": "Testing drift",
"Parameters": {
"shared_preload_libraries": "pg_stat_statements",
"track_activity_query_size": "4096"
}
}
```

Actual:
```
{
"Family": "postgres14",
"Description": "Testing drift"
}
```

---

```
parameter_group = rds.ParameterGroup(self, "ParameterGroup",
engine=rds.DatabaseInstanceEngine.postgres(
version=rds.PostgresEngineVersion.VER_14_2),
description='Testing drift',
parameters={
"shared_preload_libraries": "pg_stat_statements",
"track_activity_query_size": "4097"
}
)
```

**IN_SYNC**

Expected:
```
{
"Family": "postgres14",
"Description": "Testing drift",
"Parameters": {
"shared_preload_libraries": "pg_stat_statements",
"track_activity_query_size": "4097"
}
}
```

Actual:
```
{
"Family": "postgres14",
"Description": "Testing drift",
"Parameters": {
"track_activity_query_size": "4097"
}
}
```

### Other Details

_No response_

The issue names no repository file, test, or entry point. Start by reproducing the AWS::RDS::DBParameterGroup drift with PostgreSQL 14.2 and the three track_activity_query_size values shown; done means the configured parameters are reported consistently and a regression check covers the false-positive case.

Written by the indexing model from the issue text.