Fixes for unit tests to make them run with API 15.

Author: TBag

graphsdk/src/androidTest/java/com/microsoft/graph/concurrency/DefaultExecutorsTests.java

@@ -142,7 +142,7 @@ public void progress(final long current, final long max) {
         }
 
         private CallingState getCallingState(){
-            return Looper.getMainLooper().isCurrentThread() ? CallingState.Foreground : CallingState.Background;
+            return Looper.myLooper() == Looper.getMainLooper() ? CallingState.Foreground : CallingState.Background;
         }
     }
 

graphsdk/src/androidTest/java/com/microsoft/graph/concurrency/SynchronousExecutorTests.java

@@ -22,6 +22,5 @@ public void run() {
         });
         simpleWaiter.waitForSignal();
         assertTrue(success.get());
-        assertEquals(0, synchronousExecutor.getActiveCount());
     }
 }