Change bool, and string properties to *bool, and *string for cc

there's no use case for prepending/appending to bool, and string
properties within module struct. Declearing "*bool" and "*string" almost
cover everything user need.

I did see one case that user specify relative_install_path as
path prefix in cc_defaults, and concatenate with the one in real module
to get the final relative install path in Android.bp <bionic/tests/libs>.

Test: m -j checkbuild
Bug: b/68853585
Change-Id: If3a7a2689c3fc307aae136af6bc9c57f27a1e1a0
diff --git a/cc/proto.go b/cc/proto.go
index a235398..e7f1d41 100644
--- a/cc/proto.go
+++ b/cc/proto.go
@@ -16,7 +16,6 @@
 
 import (
 	"github.com/google/blueprint"
-	"github.com/google/blueprint/proptools"
 
 	"android/soong/android"
 )
@@ -58,7 +57,7 @@
 func protoDeps(ctx BaseModuleContext, deps Deps, p *android.ProtoProperties, static bool) Deps {
 	var lib string
 
-	switch proptools.String(p.Proto.Type) {
+	switch String(p.Proto.Type) {
 	case "full":
 		if ctx.useSdk() {
 			lib = "libprotobuf-cpp-full-ndk"
@@ -75,7 +74,7 @@
 		}
 	default:
 		ctx.PropertyErrorf("proto.type", "unknown proto type %q",
-			proptools.String(p.Proto.Type))
+			String(p.Proto.Type))
 	}
 
 	if static {