You can set up a way to implement your captioning only if the SDK supports it.
i.e., If something I wanted was introduced in Lollipop, I could use this code to make the captioning enabled.
int currentapiVersion = android.os.Build.VERSION.SDK_INT;
if (currentapiVersion >= android.os.Build.VERSION_CODES.LOLLIPOP){
// Do something for lollipop and above versions
} else{
// do something for phones running an SDK before lollipop
}
I don't believe that you are going to get captioning in an earlier release than 19 if that is where it was introduced.
Hope this helps!
Borrowed snippet from this answer here:
Retrieving Android API version programmatically