Moving new SpecTest assert to the right place (#173)

Author: schmidt-sebastian

firebase-firestore/src/test/java/com/google/firebase/firestore/spec/SpecTestCase.java

@@ -227,10 +227,6 @@ private void specSetUp(JSONObject config) {
       throw Assert.fail("The Android client does not support multi-client tests");
     }
 
-    if (config.optInt("activeClientIndex", 1) != 1) {
-      throw Assert.fail("The Android client does not support switching clients");
-    }
-
     initClient();
 
     // Set up internal event tracking for the spec tests.
@@ -741,6 +737,10 @@ private void doRestart() throws Exception {
   }
 
   private void doStep(JSONObject step) throws Exception {
+    if (step.optInt("clientIndex", 0) != 0) {
+      throw Assert.fail("The Android client does not support switching clients");
+    }
+
     if (step.has("userListen")) {
       doListen(step.getJSONArray("userListen"));
     } else if (step.has("userUnlisten")) {