ProtoLog: ensure services.core.json.gz is built deterministically

The gzip format includes a last modified timestamp, which gzip fills with the current time by default.
To avoid that, we switch to the in-tree minigzip implementation which doesn't.

Bug: 142371189
Test: make droid, verify the services.core.json.gz file is the same for repeated builds
Change-Id: Id31efe3731f922a9c960585dcb9411ffb5a4bff5