Adding Seek buttons for Android

[GyanendroKh]

Adding Forward and Backward seek buttons for Android. Fixes #615

[diegotori]

If you can accomplish this for CupertinoControls, then I would accept this PR.

@brianegan any thoughts on this proposed change, since that would be nice if users were able to seek.

[GyanendroKh]

If you can accomplish this for CupertinoControls, then I would accept this PR.

@brianegan any thoughts on this proposed change, since that would be nice if users were able to seek.

CupertinoControls already have seek buttons on the bottom bar.

https://github.com/fluttercommunity/chewie/blob/master/lib/src/cupertino/cupertino_controls.dart#L277-L279

Isn't this the one that you are referring to

[andes2912]

Please merge this PR, because Android need this feature

[Ahmadre]

Please merge this PR, because Android need this feature

We can't merge changes without investigating and the changes are done which @diegotori requested. Please update your PR accordingly and we will test this :)

[diegotori]

@Ahmadre if you have capacity, please review his changes by running them locally.

I wanna say that there were exceptions thrown due to the current library calling setState while in the middle of one.

Thanks.

[Ahmadre]

LGTM @diegotori

Your change requests seems to be implemented. We can merge this if you want.

[diegotori]

@Ahmadre can you please submit a follow-up PR that fixes lint issues related to this one? Thanks.

[diegotori]

@Ahmadre nevermind, managed to nip it when publishing 1.8.5.