Upgrade to golang protobuf api v2

Major operations:
 * Fix the go_package entries to be consistent, as the new tool
   complains when it doesn't have a '/'.
 * Regenerate with the new protoc-gen-go tool.
 * github.com/golang/protobuf -> google.golang.org/protobuf
 * proto.[Un]MarshalText -> prototext.[Un]Marshal

Change-Id: Ie1147bd2457fafb66ba555461b3bf14f0561a25d
diff --git a/ui/build/config.go b/ui/build/config.go
index cd6d549..918a956 100644
--- a/ui/build/config.go
+++ b/ui/build/config.go
@@ -25,7 +25,7 @@
 
 	"android/soong/shared"
 
-	"github.com/golang/protobuf/proto"
+	"google.golang.org/protobuf/proto"
 
 	smpb "android/soong/ui/metrics/metrics_proto"
 )
diff --git a/ui/build/config_test.go b/ui/build/config_test.go
index 7d4c76b..1f2158b 100644
--- a/ui/build/config_test.go
+++ b/ui/build/config_test.go
@@ -29,7 +29,7 @@
 	smpb "android/soong/ui/metrics/metrics_proto"
 	"android/soong/ui/status"
 
-	"github.com/golang/protobuf/proto"
+	"google.golang.org/protobuf/proto"
 )
 
 func testContext() Context {
diff --git a/ui/build/context.go b/ui/build/context.go
index 43e1e0f..f5e987e 100644
--- a/ui/build/context.go
+++ b/ui/build/context.go
@@ -20,7 +20,7 @@
 
 	"android/soong/ui/logger"
 	"android/soong/ui/metrics"
-	"android/soong/ui/metrics/metrics_proto"
+	soong_metrics_proto "android/soong/ui/metrics/metrics_proto"
 	"android/soong/ui/status"
 	"android/soong/ui/tracer"
 )
diff --git a/ui/build/soong.go b/ui/build/soong.go
index a40457f..02e7375 100644
--- a/ui/build/soong.go
+++ b/ui/build/soong.go
@@ -20,18 +20,18 @@
 	"path/filepath"
 	"strconv"
 
-	"android/soong/shared"
-	"github.com/google/blueprint/deptools"
-
+	"android/soong/ui/metrics"
 	soong_metrics_proto "android/soong/ui/metrics/metrics_proto"
+	"android/soong/ui/status"
+
+	"android/soong/shared"
+
 	"github.com/google/blueprint"
 	"github.com/google/blueprint/bootstrap"
-
-	"github.com/golang/protobuf/proto"
+	"github.com/google/blueprint/deptools"
 	"github.com/google/blueprint/microfactory"
 
-	"android/soong/ui/metrics"
-	"android/soong/ui/status"
+	"google.golang.org/protobuf/proto"
 )
 
 const (
diff --git a/ui/build/upload.go b/ui/build/upload.go
index 55ca800..55ada33 100644
--- a/ui/build/upload.go
+++ b/ui/build/upload.go
@@ -24,7 +24,8 @@
 	"time"
 
 	"android/soong/ui/metrics"
-	"github.com/golang/protobuf/proto"
+
+	"google.golang.org/protobuf/proto"
 
 	upload_proto "android/soong/ui/metrics/upload_proto"
 )