fix(java-firestore): preserve FirestoreAdminVersion.java during regeneration (#13415)

This is a followup fix for
#13397.

Fix an issue in java-firestore/owlbot.py in locating
"google-cloud-firestore-admin" that prevented the replacement logic
taking effect in FirestoreAdminStubSettings.java.

Remove the custom `Version.java` to `FirestoreAdminVersion.java`
renaming logic from owlbot.py. Instead, rely on excluding `Version.java`
during the directory move (s.move) to discard the generated version
file. `FirestoreAdminVersion.java` is added to the `keep` list in
`librarian.yaml` to preserve.

Tested regeneration locally with `go run
github.com/googleapis/librarian/cmd/librarian@${V} generate firestore`

Author: zhumin8

java-firestore/google-cloud-firestore-admin/src/main/java/com/google/cloud/firestore/v1/stub/FirestoreAdminStubSettings.java

@@ -757,7 +757,7 @@ protected LibraryMetadata getLibraryMetadata() {
     return LibraryMetadata.newBuilder()
         .setArtifactName("com.google.cloud:google-cloud-firestore")
         .setRepository("googleapis/google-cloud-java")
-        .setVersion(Version.VERSION)
+        .setVersion(FirestoreAdminVersion.VERSION)
         .build();
   }
 

java-firestore/google-cloud-firestore-admin/src/main/java/com/google/cloud/firestore/v1/stub/Version.java

@@ -33,6 +33,7 @@
 except Exception as e:
     print(f'Failed to update .repo-metadata.json: {e}')
 
+# Loop 1: License header replacements
 for library in s.get_staging_dirs():
     # put any special-case replacements here
     service = 'firestore'
@@ -41,25 +42,23 @@
     service = 'firestore-admin'
     s.replace(f'owl-bot-staging/v1/grpc-google-cloud-{service}-{version}-java/src/**/*.java', bad_license_header, license_header)
     s.replace(f'owl-bot-staging/v1/proto-google-cloud-{service}-{version}-java/src/**/*.java', bad_license_header, license_header)
-    if "firestore-admin" in str(library):
-        s.move(library, excludes=["**/Version.java"])
-        s.move(
-            f"{library}/src/main/java/com/google/cloud/firestore/v1/stub/Version.java",
-            "google-cloud-firestore-admin/src/main/java/com/google/cloud/firestore/v1/stub/FirestoreAdminVersion.java"
-        )
-        s.replace(
-            "google-cloud-firestore-admin/src/main/java/com/google/cloud/firestore/v1/stub/FirestoreAdminVersion.java",
-            "class Version",
-            "class FirestoreAdminVersion"
-        )
-        # Replace Version.VERSION with FirestoreAdminVersion.VERSION in stub files
-        s.replace(
-            "google-cloud-firestore-admin/src/main/java/com/google/cloud/firestore/v1/stub/**/*.java",
-            "Version.VERSION",
-            "FirestoreAdminVersion.VERSION",
-        )
-    else:
-        s.move(library)
+
+# Loop 2: Move libraries and handle special cases
+for version_dir in s.get_staging_dirs():
+    for library in version_dir.iterdir():
+        if not library.is_dir():
+            continue
+        if library.name == "google-cloud-firestore-admin":
+            s.move(library, excludes=["**/Version.java"])
+            # Replace Version.VERSION with FirestoreAdminVersion.VERSION in stub files
+            s.replace(
+                "google-cloud-firestore-admin/src/main/java/com/google/cloud/firestore/v1/stub/FirestoreAdminStubSettings.java",
+                "Version.VERSION",
+                "FirestoreAdminVersion.VERSION",
+            )
+        else:
+            s.move(library)
+
 s.remove_staging_dirs()
 java.common_templates(
     monorepo=True,

java-firestore/owlbot.py

@@ -1755,6 +1755,7 @@ libraries:
     keep:
       - google-cloud-firestore/src/main/resources/META-INF/native-image/com.google.cloud/google-cloud-firestore/reflect-config.json
       - google-cloud-firestore/src/test/resources/META-INF/native-image/reflect-config.json
+      - google-cloud-firestore-admin/src/main/java/com/google/cloud/firestore/v1/stub/FirestoreAdminVersion.java
       - proto-google-cloud-firestore-admin-v1/src/main/java/com/google/firestore/admin/v1/ParentName.java
       - proto-google-cloud-firestore-v1/src/main/java/com/google/firestore/v1/AnyPathName.java
       - proto-google-cloud-firestore-v1/src/main/java/com/google/firestore/v1/DatabaseRootName.java