zipalign: Remove dependency on androidfw.

Use zip_archive directly. Note that this codepath is used only
when recompressing archives with zopfli during the alignment step.
It's unclear whether this is in use at all, but I verified that the
results are identical (note the usage of the "-z" flag in the test
below).

Test: make && out/host/linux-x86/bin/zipalign -v -f -z 8 \
        out/target/product/marlin/system/app/Email/Email.apk ./out.zip

Bug: 35246701
Change-Id: I641cdb6d409cc07974d49d42c9f9e6d4f905e472