Rename no_standard_libraries to no_standard_libs

For consistency with libs and static_libs.  And make it a *bool
so that it can be overriden when used in java_defaults modules.

Test: java_test.go
Change-Id: If0eaf5d5571dc6e565056d273b0addd960d6b33f
diff --git a/java/app.go b/java/app.go
index a0c4912..e6b91a7 100644
--- a/java/app.go
+++ b/java/app.go
@@ -21,6 +21,7 @@
 	"strings"
 
 	"github.com/google/blueprint"
+	"github.com/google/blueprint/proptools"
 
 	"android/soong/android"
 )
@@ -68,7 +69,7 @@
 func (a *AndroidApp) DepsMutator(ctx android.BottomUpMutatorContext) {
 	a.Module.deps(ctx)
 
-	if !a.properties.No_standard_libraries {
+	if !proptools.Bool(a.properties.No_standard_libs) {
 		switch a.deviceProperties.Sdk_version { // TODO: Res_sdk_version?
 		case "current", "system_current", "":
 			ctx.AddDependency(ctx.Module(), frameworkResTag, "framework-res")