Service loader file missing in error prone plugin

[gtoison]

Error prone relies on the service loader mechanism to load plugin, the plugin's jar needs to contain a BugChecker file named:
META-INF\services\com.google.errorprone.bugpatterns.BugChecker

I think that since #471 the file is gone from the jar META-INF folder and the plugin is not picked up by error prone anymore.
Unless I misunderstood that file used to be generated using the annotation processor for @AutoService(BugChecker.class) here:

AutoDispose/static-analysis/autodispose-error-prone/build.gradle

Line 22 in 9e726c7

annotationProcessor deps.apt.autoService