revert E2-9593 changes for background send

(cherry picked from commit cdc49be)

Author: hrishileanplum

AndroidSDKCore/src/main/java/com/leanplum/internal/RequestOld.java

@@ -699,14 +699,7 @@ public void sendEventually() {
     if (!sent) {
       sent = true;
       Map<String, Object> args = createArgsDictionary();
-      Util.executeAsyncTask(true, new AsyncTask<Void, Void, Void>() {
-        @Override
-        protected Void doInBackground(Void... params) {
-          Map<String, Object> args = createArgsDictionary();
-          saveRequestForLater(args);
-          return null;
-        }
-      });
+      saveRequestForLater(args);
     }
     Leanplum.countAggregator().incrementCount("send_eventually");
   }

AndroidSDKTests/src/test/java/com/leanplum/internal/RequestOldTest.java

@@ -24,7 +24,6 @@
 
 import com.leanplum.Leanplum;
 import com.leanplum.__setup.LeanplumTestApp;
-import com.leanplum._whitebox.utilities.SynchronousExecutor;
 
 import junit.framework.TestCase;
 
@@ -35,7 +34,6 @@
 import org.robolectric.RobolectricTestRunner;
 import org.robolectric.RuntimeEnvironment;
 import org.robolectric.annotation.Config;
-import org.robolectric.util.ReflectionHelpers;
 
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
@@ -71,9 +69,6 @@ public void setUp() {
     Application context = RuntimeEnvironment.application;
     assertNotNull(context);
     Leanplum.setApplicationContext(context);
-
-    // Mock this so async things run synchronously
-    ReflectionHelpers.setStaticField(Util.class, "singleThreadExecutor", new SynchronousExecutor());
   }
 
   /** Test that request include a generated request id **/