Make auto-value compileOnly dependency. (#254) (#255)
Make auto-value compileOnly dependency. (#254) (#255)

Because it's not needed at runtime.  Having it in runtime classpath
triggers warnings like `warning: No processor claimed any of these
annotations: ` with error-prone compiler (grpc/grpc-java/pull/2938)
(cherry picked from commit a19c013692a0c2a61652da67add51d10ba81ebf1)
bogdandrutu/instrumentation-java,bogdandrutu/opencensus-java,songy23/instrumentation-java,dinooliva/instrumentation-java,census-instrumentation/opencensus-java,bogdandrutu/opencensus-java,sebright/opencensus-java,sebright/opencensus-java,songy23/instrumentation-java,census-instrumentation/opencensus-java,census-instrumentation/opencensus-java,bogdandrutu/opencensus-java,bogdandrutu/instrumentation-java,sebright/instrumentation-java,songy23/instrumentation-java,sebright/opencensus-java,sebright/instrumentation-java,ubschmidt2/instrumentation-java,ubschmidt2/instrumentation-java,dinooliva/instrumentation-java