NIFI-3008 Enabled expression language on BASE_DIRECTORY and FILENAME …

[jtstorck]

…properties in TailFile

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[olegz]

Just to ensure we don't have weird errors on Windows-based environments consider specifying:

"hi\n".getBytes(StandardCharsets.UTF_8);

[jtstorck]

I can make that change, but being that it's just a test for reading from the file and the test does not care about the actual output or verify the data read from the file (its just to get TailFile to read some data from the file to show that the processor is resolving the EL) is it really necessary?

[olegz]

Oh, i see, then I agree, that's ok. Will merge