Notifications not working on Android O

[andrew-codechimp]

Since updating the targetsdk to 26, notifications have stopped working as Android O does not allow background execution of intentservices from alarm manager for apps that target 26.

I see two options available.

• Roll back to targetsdk 25 unless there's a specific need for 26.
• Convert to using the job scheduler when running on devices >=21 (job scheduler only available 21 and above).

A useful article on changing to this available here https://blog.klinkerapps.com/android-o-background-services/