Improve Windows setup script Android bits
Improve Windows setup script Android bits

Changes include:
	* In case `ANDROID_HOME` environment variable is not set, try to determine the correct path to `android-sdk` through `android.bat`'s location
	* Use `android.bat` executable relative to `android-sdk`, set in `ANDROID_HOME` environment variable, for sdk updates
	* Split android sdk updates into single command calls in order to avoid problems with license agreements

NativeScript/nativescript-cli,NathanaelA/nativescript-cli,tsvetie/nativescript-cli,tsvetie/nativescript-cli,NativeScript/nativescript-cli,NathanaelA/nativescript-cli,tsvetie/nativescript-cli,NativeScript/nativescript-cli,tsvetie/nativescript-cli,NathanaelA/nativescript-cli,NativeScript/nativescript-cli,tsvetie/nativescript-cli,NathanaelA/nativescript-cli