Correctly set date and mode fields for MANIFEST.MF

The file header returned by jar.ManifestFileContents had unset
date and mode fields.  The unset date field resulted in the
"Last Mod Time" field in the zip file being set to 0, which
OpenJDK 9's jar implementation treats as an error:
java.time.DateTimeException: Invalid value for MonthOfYear (valid values 1 - 12): 0

Bug: 67095392
Test: zipdetails out/host/linux-x86/framework/tradefed.jar
Change-Id: I0a818d57420f5e5de57e8ff57791951c1b538443

1 files changed, 2 insertions, 0 deletions

diff --git a/jar/jar.go b/jar/jar.go
index f17bc98d..08fa1abd 100644
--- a/jar/jar.go
+++ b/jar/jar.go
@@ -94,6 +94,8 @@ func ManifestFileContents(src string) (*zip.FileHeader, []byte, error) {
 		Method:             zip.Store,
 		UncompressedSize64: uint64(len(b)),
 	}
+	fh.SetMode(0700)
+	fh.SetModTime(DefaultTime)
 
 	return fh, b, nil
 }