trying to upload video but getting bad request error 400
I am trying to perform a video upload in android I am getting an error 400 on the INIT method.I am using twitter4j
That sounds like you're potentially not signing the request correctly.
What version of Twitter4J are you using? I think at the moment you need to manually add a patch from Github in order to get the uploadMediaChunked method.
version of Twitter4j is 4.0.2
That's a very old version of Twitter4J - the current one is 4.0.4 and the patches to add video upload support on Github are on top of the 4.0.5 snapshot.