set all tar timestamp fields to the zero date

post-processor/compress/tar_fix_go110.go

@@ -2,10 +2,16 @@
 
 package compress
 
-import "archive/tar"
+import (
+	"archive/tar"
+	"time"
+)
 
 func setHeaderFormat(header *tar.Header) {
 	// We have to set the Format explicitly for the googlecompute-import
 	// post-processor. Google Cloud only allows importing GNU tar format.
 	header.Format = tar.FormatGNU
+	header.AccessTime = time.Time{}
+	header.ModTime = time.Time{}
+	header.ChangeTime = time.Time{}
 }