try to show the circle in the seekbar

[azisuazusa]

This PR is related to issue #42
I think this issue happened because the circle in the seek bar is not showing. So, in this PR I try to show it.

[pongponglau]

@azisuazusa, thanks a lot. I can see the circle again in Android after applying your changes. Good job.

[azisuazusa]

@pongponglau you're welcome

[kylemilloy]

Thanks for this. Been working on a lot of projects so haven't had the time to review. Will check it out sometime this week.

[pongponglau]

@azisuazusa, when i try in a read android device, I cannot easily move the seek position by dragging the circle of the seek bar. The volume bar is also not very responsive, but better than the seek bar. May i ask how i can improve the responsiveness of the seekbar and also the volume bar?

Thank you very much

[kylemilloy]

I've rebuilt the seekbar area completely and it will now show on Android (7.1.1 at least does) as well as iOS.