platform not properly prepared after previous command crash

• CLI: 6.0.2

After running preview command, and the command crashes you cannot run the project. Platform folder is not populated with all needed files and prepare is not executed correctly again on run. Build fails with: Unable to apply changes on device: ZX1G424P6K. Error is: spawn gradlew.bat ENOENT.

To Reproduce

1. tns create jsApp --js
2. tns preview
3. Scan the QR code on ios, then scan on android. The command crashes.
4. tns run android build fails. Platform android is not correctly prepared
   log.txt

Start by reproducing the crash with the listed tns create, tns preview, and tns run android commands, then inspect log.txt and the preview crash cleanup and platform preparation flow. Done means a crash during preview does not leave the Android platform incomplete, and a subsequent tns run android prepares and builds successfully.