Doesn't work with Android API 26

[erkanarslan]

I had to set API level to 25 so that it works. No problem with iOS.

[NickIliev]

@erkanarslan please provide more information on what the issue is - is your application throwing an error (if yes please post the stack trace) and what is the specific code used to reproduce the issue.

[erkanarslan]

Background http plugin or internal Android libraries show a notification in the Notification Center when uploading a file. Problem is related to that. I cannot remember it correctly but it was saying that a channel for notification is not set or incorrectly set. I learned that in API 26, you can group/classify notifications by channels. I was testing that on an emulator with Android 8.

[NickIliev]

@erkanarslan thanks for reporting this issue - as far as I see it is identical to this one which I have logged as a bug.
The plugins team will investigate and log any info in the linked issue.

Closing this one as a duplicate to #85