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/cc_test.go b/cc/cc_test.go
index b7c2395..14b4245 100644
--- a/cc/cc_test.go
+++ b/cc/cc_test.go
@@ -9,8 +9,6 @@
 	"sort"
 	"strings"
 	"testing"
-
-	"github.com/google/blueprint/proptools"
 )
 
 var buildDir string
@@ -40,7 +38,7 @@
 
 func testCc(t *testing.T, bp string) *android.TestContext {
 	config := android.TestArchConfig(buildDir, nil)
-	config.ProductVariables.DeviceVndkVersion = proptools.StringPtr("current")
+	config.ProductVariables.DeviceVndkVersion = StringPtr("current")
 
 	ctx := android.NewTestArchContext()
 	ctx.RegisterModuleType("cc_library", android.ModuleFactoryAdaptor(LibraryFactory))