[test] Fix test on user agent

The Android version number sometimes contains a `_rX` suffix.

Author: Clément Le Provost

algoliasearch/src/test/java/com/algolia/search/saas/IndexTest.java

@@ -880,7 +880,7 @@ public void doRequestCompleted(JSONObject content, AlgoliaException error) {
     public void testUserAgent() throws Exception {
         // Test the default value.
         String userAgent = (String) Whitebox.getInternalState(client, "userAgentRaw");
-        assertTrue(userAgent.matches("^Algolia for Android \\([0-9.]+\\); Android \\(([0-9.]+|unknown)\\)$"));
+        assertTrue(userAgent.matches("^Algolia for Android \\([0-9.]+\\); Android \\(([0-9.]+(_r[0-9]+)?|unknown)\\)$"));
 
         // Manipulate the list.
         assertFalse(client.hasUserAgent(new Client.LibraryVersion("toto", "6.6.6")));