Check for the presence of a germline stats file, CWL compatible.

def _has_bcftools_germline_stats(data):
    """Check for the presence of a germline stats file, CWL compatible.
    """
    stats_file = tz.get_in(["summary", "qc"], data)
    if isinstance(stats_file, dict):
        stats_file = tz.get_in(["variants", "base"], stats_file)
    if not stats_file:
        stats_file = ""
    return stats_file.find("bcftools_stats_germline") > 0