Consistently use Bool instead of proptools.Bool

Use Bool instead of proptools.Bool and String instead of proptools.String.

Test: m checkbuild
Change-Id: I32d84add9f27128c7a65413e9612fd920613584f
diff --git a/python/python.go b/python/python.go
index 4eb496a..a277988 100644
--- a/python/python.go
+++ b/python/python.go
@@ -252,9 +252,9 @@
 func (p *Module) isEmbeddedLauncherEnabled(actual_version string) bool {
 	switch actual_version {
 	case pyVersion2:
-		return proptools.Bool(p.properties.Version.Py2.Embedded_launcher)
+		return Bool(p.properties.Version.Py2.Embedded_launcher)
 	case pyVersion3:
-		return proptools.Bool(p.properties.Version.Py3.Embedded_launcher)
+		return Bool(p.properties.Version.Py3.Embedded_launcher)
 	}
 
 	return false