Check my solution, It will work.
Solutions:
First Download Subversion 1.8.13 ( 1.8 ) Download link ( https://www.visualsvn.com/downloads/ )
Then unzipped in a folder. There will have one folder "bin".
Then
Go to settings - > Version control -> Subversion
Copy the url of your downloaded svn.exe that is in bin folder that you have downloaded.
follow the pic:
Don't forget to give the end name like svn.exe last as per image.
Apply -> Ok
Restart your android studio now.
Happy Coding!