Reapply fix for IabHelper crash.

- Previously added through becc2157c47152fc4b1b781e4dad5c42cdee7936.
Bump version to 8.3.
Change log for 8.3.
Merge branch 'fix-8.3' into beta

Conflicts:
	CHANGELOG.md
	SeriesGuide/build.gradle
Prepare 9-beta2.