Auto generate userdata.img

Test: CI and unit tests
Bug: 377563861
Change-Id: I42582db31377600412d2acf0dceab5ee9e15bc58
diff --git a/android/config.go b/android/config.go
index d9db64e..10bddf7 100644
--- a/android/config.go
+++ b/android/config.go
@@ -1599,6 +1599,17 @@
 	return "oem"
 }
 
+func (c *deviceConfig) UserdataPath() string {
+	if c.config.productVariables.UserdataPath != nil {
+		return *c.config.productVariables.UserdataPath
+	}
+	return "data"
+}
+
+func (c *deviceConfig) BuildingUserdataImage() bool {
+	return proptools.Bool(c.config.productVariables.BuildingUserdataImage)
+}
+
 func (c *deviceConfig) BtConfigIncludeDir() string {
 	return String(c.config.productVariables.BtConfigIncludeDir)
 }