Replace plugin variables in all .xml files of android's plugin code

[rosen-vladimirov]

We have to replace the plugin variables in all .xml files under platforms/android part of the plugins.
When you need the plugin value in the JAVA code, you have to take it from the resources, for example from platforms/android/res/values/strings.xml. CLI replaces the plugin variables only in plugin's AndroidManifest.xml. Instead it should replace the plugin variables in all .xml files.