services: Don't track code coverage of reflection.v1 gencode

Generated code for v1alpha was ignored, but not v1. Ignoring v1 reduces
lines being checked from 16,145 to 6,303, significantly improving the
overall code coverage and removing noise. This was noticed because there
was a very clear drop at 0aa976c4 visible in the coveralls.io coverage
graph, the point when v1 was introduced.

services/build.gradle

@@ -58,6 +58,7 @@ tasks.named("jacocoTestReport").configure {
                 '**/io/grpc/binarylog/v1/**',
                 '**/io/grpc/channelz/v1/**',
                 '**/io/grpc/health/v1/**',
+                '**/io/grpc/reflection/v1/**',
                 '**/io/grpc/reflection/v1alpha/**',
         ])
     }