[aapt2] Ensure all zip entry times are the same

We want them to be all the same, so that APKs are identical if its
contents are the same, regardless of the time zone of the machine that
produced them. The accompanying change in libziparchive
(Iefc7945bff0610f8a025d4887cd5644cfa3cfb3b) ensures this.

Bug: 277978832
Test: atest aapt2_tests
Change-Id: Iab000b7c74dcb06efad41a6495b73216fd2528d6