Use soong_zip for otatools.zip and otacerts.zip

soong_zip produces more reproducible zip files that are not
affected by umask values or timestamps.

This partially reapplies I2eca2f7618e06c0b5893ff54c79261921fe051d6.

Bug: 69500920
Test: m checkbuild
Test: contents of zips is unchanged
Change-Id: Idf6fbc94e257dc34af4f5b115d740b7cb9bac015