chore: partial release script

[suztomo]

partial_release.py to take "bump-snapshot-version" as argument. These script created a change in #11804.

• apply_current_version.sh is renamed to apply_version.sh and it now takes the path to versions.txt file and "current|released" option.

To create release versions of the modules

~/google-cloud-java$ python3 .github/release/partial_release.py bump-released-version --artifact-ids=google-cloud-java,google-cloud-asset --version-type=patch
~/google-cloud-java$ cd java-asset
~/google-cloud-java/java-asset$ ../generation/apply_versions.sh ../versions.txt released

To create SNAPSHOT versions for the released modules

~/google-cloud-java$ python3 .github/release/partial_release.py bump-snapshot-version --artifact-ids=google-cloud-java,google-cloud-asset
~/google-cloud-java$ ./generation/apply_versions.sh ./versions.txt current

[meltsufin]

Can we add some tests?

[suztomo]

@meltsufin Added a unit test.