With the latest cordova-android (6.4.0) builds for different product flavors (arm, x86) do not work anymore (error e.g.: "No flavor is associated with flavor dimension ...") because of the changes introduced with gradle 3.0.0. With the new gradle plugin a flavorDimenson must be specified to build different product flavors (mentioned here in the upgrade guide. This can be fixed by adding `flavorDimensions "default"` to build.gradle if cdvBuildMultipleApks is set to true.
Another change that was introduced with the new gradle version is that builds for different architectures are put into their own directory (build/outputs/apk/<arch>/<debug|release>) which results in APK files not being found (mentioned in the upgrade guide under the point "Modifying variant outputs at build time may not work").
This can be fixed by adapting the findOutputApksHelper method in GenericBuilder.js.
An unfortunate side effect of these issues is that projects leveraging crosswalk do not work anymore.