don't fail test if we can't find strings.xml (fix #1905)

also, make sure apidemos tests run as android even if DEVICE isn't set

lib/devices/android/android.js

@@ -294,8 +294,11 @@ Android.prototype.pushStrings = function (cb) {
     logger.debug(makeStrings);
     exec(makeStrings, { maxBuffer: 524288 }, function (err, stdout, stderr) {
       if (err) {
+        // if we can't get strings, just dump an empty json and continue
+        logger.warn("Error getting strings.xml from apk");
         logger.debug(stderr);
-        return cb(new Error("Could not make strings from apk"));
+        var remoteFile = path.resolve(remotePath, stringsJson);
+        return this.adb.shell("echo '{}' > " + remoteFile, cb);
       }
       var jsonFile = path.resolve(outputPath, stringsJson);
       this.adb.push(jsonFile, remotePath, function (err) {

test/functional/android/apidemos/desired.js

@@ -3,7 +3,8 @@
 var getAppPath = require('../../../helpers/app').getAppPath;
 
 module.exports = {
-  app: getAppPath('ApiDemos'),
+  app: getAppPath('ApiDemos', 'android'),
+  device: 'Android',
   'app-package': 'com.example.android.apis',
   'app-activity': '.ApiDemos'
 };

test/helpers/app.js

@@ -3,7 +3,14 @@
 var env = require('./env'),
     path = require('path');
 
-module.exports.getAppPath = function (app) {
+module.exports.getAppPath = function (app, device) {
+  if (device && device[0] === "i") {
+    env.IOS = true;
+    env.ANDROID = false;
+  } else if (device && device.toLowerCase() === "android") {
+    env.ANDROID = true;
+    env.IOS = false;
+  }
   if (env.IOS) {
     return path.resolve(__dirname, "../../sample-code/apps/" + app +
       "/build/Release-iphonesimulator/" + app + ".app");