types: consistently name generated protos

Rename each generated protobuf package such that the base of the
Go package path is always equal to the Go package name to follow
proper Go package naming conventions.

The Go package name is derived from the .proto source file name by
replacing ".proto" with "pb" and stripping all underscores.

Change-Id: Iea05d1b5d94b1b2821ae10276ab771bb2df93c0e
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/177380
Reviewed-by: Damien Neil <dneil@google.com>
diff --git a/reflect/protodesc/protodesc_test.go b/reflect/protodesc/protodesc_test.go
index bbaaef5..19c3ab3 100644
--- a/reflect/protodesc/protodesc_test.go
+++ b/reflect/protodesc/protodesc_test.go
@@ -7,7 +7,7 @@
 	"google.golang.org/protobuf/internal/scalar"
 	"google.golang.org/protobuf/reflect/protoregistry"
 
-	descriptorpb "google.golang.org/protobuf/types/descriptor"
+	"google.golang.org/protobuf/types/descriptorpb"
 )
 
 // Tests validation logic for malformed descriptors.