Force gradle to use root package.json

I don't know what evidence it would have that it should do otherwise, but this explicitly
tells it to do the right thing.

Author: rye

android/app/build.gradle

@@ -219,6 +219,7 @@ task copyDownloadableDepsToLibs(type: Copy) {
 
 // Bundles the app's data for the build process
 task bundleData(type: Exec) {
+    workingDir '../../'
     commandLine 'npm', 'run', 'bundle-data'
 }