android-interop-testing: correct order in assertEquals (#4810)

diff --git a/android-interop-testing/app/src/androidTest/java/io/grpc/android/integrationtest/InteropInstrumentationTest.java b/android-interop-testing/app/src/androidTest/java/io/grpc/android/integrationtest/InteropInstrumentationTest.java
index 3fe6379..47f6fc7 100644
--- a/android-interop-testing/app/src/androidTest/java/io/grpc/android/integrationtest/InteropInstrumentationTest.java
+++ b/android-interop-testing/app/src/androidTest/java/io/grpc/android/integrationtest/InteropInstrumentationTest.java
@@ -131,6 +131,6 @@
             testCase)
         .execute();
     String result = resultFuture.get(TIMEOUT_SECONDS, TimeUnit.SECONDS);
-    assertEquals(testCase + " failed", result, InteropTask.SUCCESS_MESSAGE);
+    assertEquals(testCase + " failed", InteropTask.SUCCESS_MESSAGE, result);
   }
 }