Increase timeout on FollowIndexSecurityIT.testAutoFollowPatterns (elastic#50282)

This test was causing test failures on slow CI runs.

Closes elastic#50279

Author: ywelsch

x-pack/plugin/ccr/qa/security/src/test/java/org/elasticsearch/xpack/ccr/FollowIndexSecurityIT.java

@@ -169,7 +169,7 @@ public void testAutoFollowPatterns() throws Exception {
         assertBusy(() -> {
             ensureYellow(allowedIndex);
             verifyDocuments(allowedIndex, 5, "*:*");
-        });
+        }, 30, TimeUnit.SECONDS);
         assertThat(indexExists(disallowedIndex), is(false));
         assertBusy(() -> {
             verifyCcrMonitoring(allowedIndex, allowedIndex);