bring back config for java-bigtable

Author: JoeWang1127

library_generation/test/integration_tests.py

@@ -125,7 +125,8 @@ def __get_config_files(cls, path: str) -> Dict[str, str]:
         config_files = {}
         for sub_dir in Path(path).resolve().iterdir():
             repo = sub_dir.name
-            if repo == "golden":
+            # skip the split repo.
+            if repo == "golden" or repo == "java-bigtable":
                 continue
             config = f"{sub_dir}/{config_name}"
             config_files[repo] = config

library_generation/test/resources/integration/java-bigtable/generation_config.yaml

@@ -0,0 +1,14 @@
+gapic_generator_version: 2.32.0
+grpc_version: 1.61.0
+protobuf_version: 23.2
+googleapis_commitish: 4512234113a18c1fda1fb0d0ceac8f4b4efe9801
+owlbot_cli_image: sha256:623647ee79ac605858d09e60c1382a716c125fb776f69301b72de1cd35d49409
+synthtool_commitish: 6612ab8f3afcd5e292aecd647f0fa68812c9f5b5
+destination_path: java-bigtable
+libraries:
+- api_shortname: bigtable
+  name_pretty: Cloud Bigtable
+  library_type: GAPIC_COMBO
+  GAPICs:
+  - proto_path: google/bigtable/admin/v2
+  - proto_path: google/bigtable/v2