Add Goma deprecation PSA to soong.

Test: build with Goma
Change-Id: Ie7e146285afd40bc0a1dc17a0b898960f57a118b

cmd/soong_ui/main.go

@@ -173,6 +173,7 @@ func main() {
 	rbeMetricsFile := filepath.Join(logsDir, c.logsPrefix+"rbe_metrics.pb")
 	soongMetricsFile := filepath.Join(logsDir, c.logsPrefix+"soong_metrics")
 	defer build.UploadMetrics(buildCtx, config, c.simpleOutput, buildStarted, buildErrorFile, rbeMetricsFile, soongMetricsFile)
+	defer build.PrintGomaDeprecation(buildCtx, config)
 
 	os.MkdirAll(logsDir, 0777)
 	log.SetOutput(filepath.Join(logsDir, c.logsPrefix+"soong.log"))

ui/build/rbe.go

@@ -128,3 +128,13 @@ func DumpRBEMetrics(ctx Context, config Config, filename string) {
 		ctx.Fatalf("failed to copy %q to %q: %v\n", metricsFile, filename, err)
 	}
 }
+
+// PrintGomaDeprecation prints a PSA on the deprecation of Goma if it is set for the build.
+func PrintGomaDeprecation(ctx Context, config Config) {
+	if config.UseGoma() {
+		fmt.Fprintln(ctx.Writer, "")
+		fmt.Fprintln(ctx.Writer, "Goma for Android is being deprecated and replaced with RBE.")
+		fmt.Fprintln(ctx.Writer, "See go/goma_android_deprecation for more details.")
+		fmt.Fprintln(ctx.Writer, "")
+	}
+}