Error while using customGcsTempLocation() with Dataflow

I have the following code snippet which writes content to BigQuery via File Loads.

Currently the files are being written to a GCS Bucket, but I want to write them to the local file storage of Dataflow instead and want BigQuery to load data from there.

 
```

BigQueryIO
.writeTableRows()
.withNumFileShards(100)
.withTriggeringFrequency(Duration.standardSeconds(90))

.withMethod(BigQueryIO.Write.Method.FILE_LOADS)
.withSchema(getSchema())
.withoutValidation()

.withCustomGcsTempLocation(new ValueProvider() {
   @Override
   public String get(){

        return "/home/harshit/testFiles";    
}
    @Override
   public boolean isAccessible(){

        return true;    
}})
.withTimePartitioning(new TimePartitioning().setType("DAY"))

.withCreateDisposition(BigQueryIO.Write.CreateDisposition.CREATE_IF_NEEDED)
.withWriteDisposition(BigQueryIO.Write.WriteDisposition.WRITE_APPEND)

.to(tableName));

```

On running this, I don't see any files being written to the provided path and the BQ load jobs fail with an IOException.

I looked at the docs, but I was unable to find any working example for this.

Imported from Jira [BEAM-8089](https://issues.apache.org/jira/browse/BEAM-8089). Original Jira may contain additional context.
Reported by: the-dagger.