Properly skip OnDemandBlockSnapshotIndexInputTests.testVariousBlockSi…

…ze on Windows.

PR opensearch-project#5397 skipped this test in @before block but still
frequently throws a TestCouldNotBeSkippedException.  This is caused by the after block still executing and throwing  an exception
while cleaning the directory created at the path in @before.  Moving the assumption to the individual test prevents this exception by ensuring the path exists.

Signed-off-by: Marc Handalian <handalm@amazon.com>

server/src/test/java/org/opensearch/index/store/remote/file/OnDemandBlockSnapshotIndexInputTests.java

@@ -53,7 +53,6 @@ public class OnDemandBlockSnapshotIndexInputTests extends OpenSearchTestCase {
 
     @Before
     public void init() {
-        assumeFalse("Awaiting Windows fix https://github.com/opensearch-project/OpenSearch/issues/5396", Constants.WINDOWS);
         transferManager = mock(TransferManager.class);
         lockFactory = SimpleFSLockFactory.INSTANCE;
         path = LuceneTestCase.createTempDir("OnDemandBlockSnapshotIndexInputTests");
@@ -69,6 +68,7 @@ public void clean() {
     }
 
     public void testVariousBlockSize() throws Exception {
+        assumeFalse("Awaiting Windows fix https://github.com/opensearch-project/OpenSearch/issues/5396", Constants.WINDOWS);
         int fileSize = 29360128;
         int blockSizeShift;