Apply suggestion from @sadanand48

Co-authored-by: Sadanand Shenoy <sadanand.shenoy4898@gmail.com>

Author: ChenSammi

hadoop-ozone/integration-test/src/test/java/org/apache/hadoop/ozone/om/TestOMRatisSnapshots.java

@@ -965,6 +965,7 @@ public void testInstallSnapshotOzoneManagerNotInRunningState() throws Exception
     OzoneManager.setTestInstallSnapshot(true);
     LogCapturer logCapture = LogCapturer.captureLogs(OzoneManager.class);
     assertLogCapture(logCapture, "OzoneManager is not in running state");
+    GenericTestUtils.waitFor(followerOM::isRunning, 100, 30_000);
     OzoneManager.setTestInstallSnapshot(false);
 
     // The recently started OM should be lagging behind the leader OM.