Add status messages for RBE and product config

RBE adds a lot of time to m nothing builds,
so add status messages for it so that it's not misattributed
to some other part of the build.

Bug: 269644490
Test: m nothing
Change-Id: Ifff11bfc88f43b559526f3e3d3022c1388e42156
diff --git a/ui/build/dumpvars.go b/ui/build/dumpvars.go
index 1e3e547..a9c298f 100644
--- a/ui/build/dumpvars.go
+++ b/ui/build/dumpvars.go
@@ -84,6 +84,14 @@
 	ctx.BeginTrace(metrics.RunKati, "dumpvars")
 	defer ctx.EndTrace()
 
+	tool := ctx.Status.StartTool()
+	if write_soong_vars {
+		// only print this when write_soong_vars is true so that it's not printed when using
+		// the get_build_var command.
+		tool.Status("Running product configuration...")
+	}
+	defer tool.Finish()
+
 	cmd := Command(ctx, config, "dumpvars",
 		config.PrebuiltBuildTool("ckati"),
 		"-f", "build/make/core/config.mk",
@@ -108,7 +116,7 @@
 	}
 	cmd.StartOrFatal()
 	// TODO: error out when Stderr contains any content
-	status.KatiReader(ctx.Status.StartTool(), pipe)
+	status.KatiReader(tool, pipe)
 	cmd.WaitOrFatal()
 
 	ret := make(map[string]string, len(vars))