* Rework Android NDKs
* Minor fix
* Fix variable name
* Minor fixes
* Reword Android env vars table
* Remove Android env vars table from doc file
* Rework to use only major ndk versions in toolset
* Fix ndk paths
* Fix win2016 toolset
* Refactor
* Minor fix
* Fix ndk tests
* Add Android SDKs tests
* Fix path to android helpers
* Fix path to sdkmanager
* Remove extra and add-ons tests
* Add verbose option to sdkmanager
* Add additional tools test
* Fix extra and addons tests
* Fix extra and addons android packages
* Fix image templates