Do not read 'vendor_available: false'

In case of VNDK, 'vendor_available: false' had a special meaning that
defines VNDK-private libraries. It is not trivial because not
defining a boolean property means 'false' normally. To avoid the
confusion replace it with the 'vndk.private: true' for VNDK-private
libraries and 'private: true' for LLNDK-private libraries.

All VNDK libraries must define 'vendor_available: true' and may have
'vndk.private: true' if they are VNDK-private.
With this change '(vendor|product)_available: false' is the same as
not defining the property.

LLNDK-private must define 'private: true' instead of
'vendor_available: false'.

Bug: 175768895
Test: build
Change-Id: I57fbca351be317257d95027f3cdcdbbe537eab23
diff --git a/cc/cc_test.go b/cc/cc_test.go
index 2d02a6a..09b728e 100644
--- a/cc/cc_test.go
+++ b/cc/cc_test.go
@@ -234,9 +234,6 @@
 	t.Helper()
 
 	mod := ctx.ModuleForTests(name, variant).Module().(*Module)
-	if !mod.HasVendorVariant() {
-		t.Errorf("%q must have variant %q", name, variant)
-	}
 
 	// Check library properties.
 	lib, ok := mod.compiler.(*libraryDecorator)
@@ -730,10 +727,11 @@
 		}
 		cc_library {
 			name: "libvndk-private",
-			vendor_available: false,
-			product_available: false,
+			vendor_available: true,
+			product_available: true,
 			vndk: {
 				enabled: true,
+				private: true,
 			},
 			nocrt: true,
 		}
@@ -757,7 +755,7 @@
 
 func TestVndkModuleError(t *testing.T) {
 	// Check the error message for vendor_available and product_available properties.
-	testCcErrorProductVndk(t, "vndk: vendor_available must be set to either true or false when `vndk: {enabled: true}`", `
+	testCcErrorProductVndk(t, "vndk: vendor_available must be set to true when `vndk: {enabled: true}`", `
 		cc_library {
 			name: "libvndk",
 			vndk: {
@@ -767,7 +765,7 @@
 		}
 	`)
 
-	testCcErrorProductVndk(t, "vndk: vendor_available must be set to either true or false when `vndk: {enabled: true}`", `
+	testCcErrorProductVndk(t, "vndk: vendor_available must be set to true when `vndk: {enabled: true}`", `
 		cc_library {
 			name: "libvndk",
 			product_available: true,
@@ -3136,7 +3134,7 @@
 		}
 		llndk_library {
 			name: "libllndkprivate.llndk",
-			vendor_available: false,
+			private: true,
 			symbol_file: "",
 		}`