chore: do not distinguish monorepo or split repo when using git add in generation workflow (#11115)

* chore: update hermetic gen workflow

* update config

* update config

Author: JoeWang1127

.github/scripts/hermetic_library_generation.sh

@@ -21,7 +21,9 @@ set -e
 # The parameters of this script is:
 # 1. target_branch, the branch into which the pull request is merged.
 # 2. current_branch, the branch with which the pull request is associated.
-# 3. [optional] generation_config, the path to the generation configuration,
+# 3. [optional] image_tag, the tag of gcr.io/cloud-devrel-public-resources/java-library-generation.
+# The value will be parsed from the generation configuration if not specified.
+# 4. [optional] generation_config, the path to the generation configuration,
 # the default value is generation_config.yaml in the repository root.
 while [[ $# -gt 0 ]]; do
 key="$1"
@@ -34,6 +36,10 @@ case "${key}" in
     current_branch="$2"
     shift
     ;;
+  --image_tag)
+    image_tag="$2"
+    shift
+    ;;
   --generation_config)
     generation_config="$2"
     shift
@@ -56,6 +62,10 @@ if [ -z "${current_branch}" ]; then
   exit 1
 fi
 
+if [ -z "${image_tag}" ]; then
+  image_tag=$(grep "gapic_generator_version" "${generation_config}" | cut -d ':' -f 2 | xargs)
+fi
+
 if [ -z "${generation_config}" ]; then
   generation_config=generation_config.yaml
   echo "Using default generation config: ${generation_config}"
@@ -96,13 +106,8 @@ docker run \
   --current-generation-config-path="${workspace_name}/${generation_config}"
 
 # commit the change to the pull request.
-if [[ $(basename "$(pwd)") == "google-cloud-java" ]]; then
-  git add java-* pom.xml gapic-libraries-bom/pom.xml versions.txt
-else
-  # The image leaves intermediate folders and files it works with. Here we remove them
-  rm -rdf output googleapis "${baseline_generation_config}"
-  git add --all -- ':!pr_description.txt'
-fi
+rm -rdf output googleapis "${baseline_generation_config}"
+git add --all -- ':!pr_description.txt'
 changed_files=$(git diff --cached --name-only)
 if [[ "${changed_files}" == "" ]]; then
     echo "There is no generated code change with the generation config change ${config_diff}."