Fix testMalformedToken (#50164)

This test was fixed as part of #49736 so that it used a
TokenService mock instance that was enabled, so that token
verification fails because the token is invalid and not because
the token service is not enabled.
When the randomly generated token we send, decodes to being of
version > 7.2 , we need to have mocked a GetResponse for the call
that TokenService#getUserTokenFromId will make, otherwise this
hangs and times out.

x-pack/plugin/security/src/test/java/org/elasticsearch/xpack/security/authc/TokenServiceTests.java

@@ -599,7 +599,9 @@ public void testMalformedToken() throws Exception {
         final byte[] randomBytes = new byte[numBytes];
         random().nextBytes(randomBytes);
         TokenService tokenService = createTokenService(tokenServiceEnabledSettings, systemUTC());
-
+        // mock another random token so that we don't find a token in TokenService#getUserTokenFromId
+        Authentication authentication = new Authentication(new User("joe", "admin"), new RealmRef("native_realm", "native", "node1"), null);
+        mockGetTokenFromId(tokenService, UUIDs.randomBase64UUID(), authentication, false);
         ThreadContext requestContext = new ThreadContext(Settings.EMPTY);
         storeTokenHeader(requestContext, Base64.getEncoder().encodeToString(randomBytes));