Bump jib format_version to support new devkit archive layout

With the new devkits I deployed recently, the file layout changed as a top level directory inside the tar archive was introduced. This works in most cases, but there are certain situations where jib does not handle this well. This causes AOT testing on Linux to stop working with the run-test-prebuilt make target.

This issue is being fixed in Jib, but the fix (which is generally for the better) changes behavior that will break other aspects of existing jib-profiles.js files, so will require a bump in the format_version to be activated. This issue will make that bump, along any other modifications to be compatible with the new format_version.