feat(storage:oci): format code and improve the toString

Author: jiafu1115

storage/oci/src/main/java/io/aiven/kafka/tieredstorage/storage/oci/OciStorage.java

@@ -75,12 +75,12 @@ OciUploadOutputStream ociOutputStream(final ObjectKey key) {
     @Override
     public void delete(final ObjectKey key) throws StorageBackendException {
         try {
-            final DeleteObjectRequest deleteRequest = DeleteObjectRequest.builder()
+            final DeleteObjectRequest deleteObjectRequest = DeleteObjectRequest.builder()
                     .namespaceName(namespaceName)
                     .bucketName(bucketName)
                     .objectName(key.value())
                     .build();
-            objectStorageClient.deleteObject(deleteRequest);
+            objectStorageClient.deleteObject(deleteObjectRequest);
         } catch (final BmcException e) {
             throw new StorageBackendException("Failed to delete " + key, e);
         }
@@ -119,13 +119,13 @@ public InputStream fetch(final ObjectKey key, final BytesRange range) throws Sto
                 return InputStream.nullInputStream();
             }
 
-            final GetObjectRequest getRequest = GetObjectRequest.builder()
+            final GetObjectRequest getObjectRequest = GetObjectRequest.builder()
                  .namespaceName(namespaceName)
                 .bucketName(bucketName)
                 .objectName(key.value())
                 .range(formatRange(range))
                 .build();
-            return objectStorageClient.getObject(getRequest).getInputStream();
+            return objectStorageClient.getObject(getObjectRequest).getInputStream();
         } catch (final BmcException e) {
             if (e.getStatusCode() == 404) {
                 throw new KeyNotFoundException(this, key, e);
@@ -147,7 +147,8 @@ public String toString() {
         return "OciStorage{"
             + "namespaceName='" + namespaceName + '\''
             + "bucketName='" + bucketName + '\''
-            + ", partSize=" + partSize
+            + ", partSize=" + partSize + '\''
+            + ", storageTier=" + storageTier
             + '}';
     }
 }