Turn on HINT_FROM_SOONG by default

In most case, turning on HINT_FROM_SOONG improves build performance even
though a model is not so accurate. At least, it doesn't cause
performance regression (very likely)

Bug: 275458825
Test: m
Change-Id: Ie4ff69e68a93f6f0db3d060980657ae623816b2b

ui/build/config.go

@@ -313,8 +313,9 @@ func UploadOnlyConfig(ctx Context, _ ...string) Config {
 
 func NewConfig(ctx Context, args ...string) Config {
 	ret := &configImpl{
-		environ:       OsEnvironment(),
-		sandboxConfig: &SandboxConfig{},
+		environ:               OsEnvironment(),
+		sandboxConfig:         &SandboxConfig{},
+		ninjaWeightListSource: HINT_FROM_SOONG,
 	}
 
 	// Default matching ninja