Fix, cleaner code

[Alexays]

Ok so in this PR what i have done :

• close Get oneshot updated location :) #6
• Cleaner android code
• Better Android permission support
  ex: Opens settings to enable location
• Fix: stream will not close

Open to review :)

[Lyokone]

Hi I cannot find the firstWhere function in your code, is it implemented ? :)

[Alexays]

@Lyokone firstWhere is a dart function ;)

[Lyokone]

Oh okay didn't knew that ! Thanks !

[Lyokone]

Thanks a lot !! :)