allow pushStrings to work with 'app' as package, not just file

fix #2749 and add tests
also fix tryNTimes, I think it was vacuously succeeding all the time
(cc @sebv)

lib/devices/android/android-common.js

@@ -62,7 +62,7 @@ androidCommon.configureApp = function (cb) {
 
   if (this.appIsPackageOrBundle(this.args.app)) {
     // we have a package instead of app
-    this.args.androidPackage = this.args.app;
+    this.args.appPackage = this.args.app;
     this.args.app = null;
     logger.debug("App is an Android package, will attempt to run on device");
     cb();

test/functional/android/apidemos/basic-specs.js

@@ -187,11 +187,10 @@ describe("apidemo - basic @skip-ci", function () {
         try3Times(function () {
           return session.setUp(title)
             .catch(function (err) { throw err.data; })
-            .should.be.rejectedWith(/Error locating the app/);
+            .should.eventually.be.rejectedWith(/Error locating the app/);
         }).nodeify(done);
       });
     });
-
   });
 
   describe('pre-existing uiautomator session', function () {
@@ -259,6 +258,14 @@ describe("apidemo - basic @skip-ci", function () {
       session.setUp(title + "- zip url").nodeify(done);
     });
 
+    it('should load an app via package', function (done) {
+      var caps = _.clone(desired);
+      caps.app = 'io.appium.android.apis';
+      caps.appActivity = '.ApiDemos';
+      session = initSession(caps, desired);
+      session.setUp(title + "- package").nodeify(done);
+    });
+
   });
 
 });

test/helpers/repeat.js

@@ -1,7 +1,7 @@
 "use strict";
 
 var tryNTimes = function (n, fn) {
-  if (n <= 0) return;
+  if (n === 1) return fn();
   return fn().catch(function () {
     return tryNTimes(n - 1, fn);
   });