Support latest Android Studio and cli gradle

Modified AndroidManifest and gradle build files to properly include .so
files inside of the apk. This also allows support for the latest version
of Android Studio or building at the command line with ./gradlew
assemble
Add README file for sample project build steps

Added a README file to the projects/android directory to describe the
command line steps to assemble the apk and install it to a device.
Update README.md

Fixing styling
Merge pull request #90 from Barryrowe/support-new-android-studio

Support latest Android Studio and cli gradle