ZipWriter: Do not write DataDescriptor for STORED files

Older implementations of ZIP (Java's ZipInputStream) don't
like a Data Descriptor trailing after an uncompressed entry.

If the FILE is seekable, and the entry is uncompressed, seek
back to the header and write out the crc and sizes.

Bug: 36686974
Test: make ziparchive_tests
Change-Id: I61664515e5afa3e2ba814874eeac847a2aaac319