Upgrade google-http-client and google-http-client-gson.

In bazelbuild#15176 we upgraded google-auth-library-oauth2-http to 1.6.0, but didn't
upgrade its dependencies accordingly; Maven claims 1.41.4 is needed [1].
In turn, a new transitive dependency on opencensus-contrib-http-util 0.31.0
also becomes necessary [2].

[1] https://mvnrepository.com/artifact/com.google.auth/google-auth-library-oauth2-http/1.6.0
[2] https://mvnrepository.com/artifact/com.google.http-client/google-http-client/1.41.4

third_party/BUILD

@@ -165,8 +165,8 @@ distrib_java_import(
     jars = [
         "api_client/google-api-client-1.22.0.jar",
         "api_client/google-api-client-gson-1.22.0.jar",
-        "api_client/google-http-client-1.22.0-SNAPSHOT.jar",
-        "api_client/google-http-client-gson-1.22.0.jar",
+        "api_client/google-http-client-1.41.4.jar",
+        "api_client/google-http-client-gson-1.41.4.jar",
     ],
     runtime_deps = [
         ":gson",
@@ -508,6 +508,7 @@ distrib_java_import(
     jars = [
         "opencensus/opencensus-api-0.24.0.jar",
         "opencensus/opencensus-contrib-grpc-metrics-0.24.0.jar",
+        "opencensus/opencensus-contrib-http-util-0.31.0.jar",
     ],
 )