Support system/vendor for devices without a vendor partition

Test: lunch aosp_arm-eng; m -j vulkan.default
Change-Id: I91eabf98f53c455ec4ade95215f11a6f89631747

android/config.go

@@ -443,6 +443,13 @@ func (c *deviceConfig) Arches() []Arch {
 	return arches
 }
 
+func (c *deviceConfig) VendorPath() string {
+	if c.config.ProductVariables.VendorPath != nil {
+		return *c.config.ProductVariables.VendorPath
+	}
+	return "vendor"
+}
+
 func (c *deviceConfig) VndkVersion() string {
 	if c.config.ProductVariables.DeviceVndkVersion == nil {
 		return ""

android/paths.go

@@ -631,7 +631,7 @@ func PathForModuleInstall(ctx ModuleContext, paths ...string) OutputPath {
 	if ctx.Device() {
 		partition := "system"
 		if ctx.Proprietary() {
-			partition = "vendor"
+			partition = ctx.DeviceConfig().VendorPath()
 		}
 		if ctx.InstallInData() {
 			partition = "data"

android/variable.go

@@ -113,6 +113,8 @@ type productVariables struct {
 	UseGoma                    *bool `json:",omitempty"`
 	Debuggable                 *bool `json:",omitempty"`
 
+	VendorPath *string `json:",omitempty"`
+
 	ClangTidy  *bool   `json:",omitempty"`
 	TidyChecks *string `json:",omitempty"`