DLPX-88225 Automated hotfix process leads to hotfix branch engine version always being set as latest engine version TOOL-23229 Improvements to masking/containerized-masking/virtualization linux-pkg handling

[sonamkindy]

Problem

[DLPX-88225](https://delphix.atlassian.net/browse/DLPX-88225) The earlier change checked into dms-core-gate at https://github.com/delphix/dms-core-gate/pull/251 unfortunately introduced a slew of issues, including the automated hotfix process not picking up the right engine version for the given hotfix. [TOOL-23229](https://delphix.atlassian.net/browse/TOOL-23229) We should reduce repetition when it comes to passing the secret build args needed to fetch secrets from the AWS secret store.

Solution

[DLPX-88225](https://delphix.atlassian.net/browse/DLPX-88225) The environment variable `DELPHIX_RELEASE_VERSION` is what we actually care about - if that's set, we can directly pass it as a gradle property via the gradle command (that way, the dms-core-gate get-branch-version.sh shell script doesn't get executed at all). [TOOL-23229](https://delphix.atlassian.net/browse/TOOL-23229) Add a function in `lib/common.sh` that can be used by the virtualization, masking and containerized-masking linux-pkg jobs.

Testing Done

``` ❯ git-ab-pre-push -b "masking virtualization" Running `git push -f origin fa96e214f6469d599f4e60f4ba343181da9872b3:refs/heads/dlpx/test/___develop___/sonamkindy/fa96e214f6469d599f4e60f4ba343181da9872b3` Your build is at: http://selfservice.jenkins.delphix.com/job/appliance-build-orchestrator-pre-push/7291/ ``` http://selfservice.jenkins.delphix.com/job/appliance-build-orchestrator-pre-push/7291/