Fix HiveContext classloading for GCS connector.

IsolatedClientLoader.isSharedClass includes all of com.google.*, presumably
for Guava, protobuf, and/or other shared Google libraries, but needs to
count com.google.cloud.* as "hive classes" when determining which ClassLoader
to use. Otherwise, things like HiveContext.parquetFile will throw a
ClassCastException when fs.defaultFS is set to a Google Cloud Storage (gs://)
path. On StackOverflow: http://stackoverflow.com/questions/31478955

sql/hive/src/main/scala/org/apache/spark/sql/hive/client/IsolatedClientLoader.scala

@@ -125,7 +125,7 @@ private[hive] class IsolatedClientLoader(
     name.contains("log4j") ||
     name.startsWith("org.apache.spark.") ||
     name.startsWith("scala.") ||
-    name.startsWith("com.google") ||
+    (name.startsWith("com.google") && !name.startsWith("com.google.cloud")) ||
     name.startsWith("java.lang.") ||
     name.startsWith("java.net") ||
     sharedPrefixes.exists(name.startsWith)