[ABFS]: FooterReadBufferSize should not be greater than readBufferSize

The method `optimisedRead` creates a buffer array of size `readBufferSize`. If footerReadBufferSize is greater than readBufferSize, abfs will attempt to read more data than the buffer array can hold, which causes an exception.

Change: To avoid this, we will keep footerBufferSize = min(readBufferSizeConfig, footerBufferSizeConfig)