There were a few API changes, mostly around explicitly creating
Services/Activities/ContentProvider instances, but they were pretty
easy to address.

Sadly, Robolectric doesn't really work with the new aapt2 processing
in Android-Gradle plugin 3.0+ -- see in particular
https://github.com/robolectric/robolectric/issues/3333#issuecomment-324300418
-- so we have to opt-out of the new implementation for now.  Hopefully
plugin 3.1+ will address these issues, which are widespread.

MozReview-Commit-ID: dlbd32kMs6

--HG--
extra : rebase_source : fe30729161e5dc91ea9173f9b7aaa9135d096791
extra : source : 690e265c684ce70ecb89355314fd1574bb421f0b