Fix this crash I see when building for android:
```
:app:generateBundledResourcesHashDebug
module.js:471
throw err;
^
Error: Cannot find module '/var/folders/94/wngs1jw91_n2_jjjrfljtqrc0000gn/T/CodePushResourcesMap-1b95774b.json'
```
Looks like these two tasks (`recordFileBeforeBundleCommand` and `generateBundledResourcesHash`) run in parallel, which create problems because one depends on a file generated by the other. Not sure why others don't have this issue, though, but I suspect this is exactly the issue reported in https://github.com/Microsoft/react-native-code-push/issues/836
Remove `assetsDir` variable, as `generateBundledResourcesHash.js` should output `CodePushHash.json` to `jsBundleDir${targetName}` folder, and not the hardcoded `$buildDir/intermediates/assets/${targetPath}` one.
In case version of 'Android Plugin for Gradle'' is lower than 1.3.0
'$buildDir' has slightly different structure - 'merged' folder
does not exists so '${targetPath}' folder contains directly in 'res' folder.
Fix issue https://github.com/Microsoft/react-native-code-push/issues/584
