Fix FileWatcherAssayIntegrationTest after FileLike refactor

[labkey-jeckels]

Rationale

java.lang.AssertionError
	at org.labkey.api.util.FileUtil.readHeader(FileUtil.java:1490)
	at org.labkey.api.reader.ExcelLoader.isExcel(ExcelLoader.java:119)
	at org.labkey.assay.pipeline.AssayImportRunTask$FileAnalysisFactory.getRawData(AssayImportRunTask.java:244)
	at org.labkey.assay.pipeline.AssayImportRunTask.run(AssayImportRunTask.java:819)
	at org.labkey.api.pipeline.PipelineJob.runActiveTask(PipelineJob.java:844)
	at org.labkey.api.pipeline.PipelineJob.run(PipelineJob.java:1092)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:539)

Successful run in FB:

https://teamcity.labkey.org/buildConfiguration/LabkeyTrunk_GitPostgres/3757887

Changes

• Wrap with BufferedInputStream