Force dumpvars into dumb terminal mode and move log files

Force soong_ui in dumpvars mode to use a dumb terminal so that it
doesn't print an empty status table.  Also move the logs to files
that are prefixed with "dumpvars-" so that they don't rotate the
real build logs.

Fixes: 139307849
Test: lunch
Change-Id: If92421af07731fedc9ca42670f309e95922a2224

cmd/multiproduct_kati/main.go

@@ -158,7 +158,7 @@ type mpContext struct {
 func main() {
 	stdio := terminal.StdioImpl{}
 
-	output := terminal.NewStatusOutput(stdio.Stdout(), "",
+	output := terminal.NewStatusOutput(stdio.Stdout(), "", false,
 		build.OsEnvironment().IsEnvTrue("ANDROID_QUIET_BUILD"))
 
 	log := logger.New(output)
@@ -391,7 +391,7 @@ func buildProduct(mpctx *mpContext, product string) {
 		Thread:  mpctx.Tracer.NewThread(product),
 		Status:  &status.Status{},
 	}}
-	ctx.Status.AddOutput(terminal.NewStatusOutput(ctx.Writer, "",
+	ctx.Status.AddOutput(terminal.NewStatusOutput(ctx.Writer, "", false,
 		build.OsEnvironment().IsEnvTrue("ANDROID_QUIET_BUILD")))
 
 	config := build.NewConfig(ctx, flag.Args()...)