Fix crash when missing platform sdk version

Fixes: 277890306
Test: Presubmits
Change-Id: I26658a90856cb057c631bb71ca0cd094ed648cf5
diff --git a/android/config.go b/android/config.go
index 2ccb732..2904581 100644
--- a/android/config.go
+++ b/android/config.go
@@ -833,6 +833,10 @@
 	return uncheckedFinalApiLevel(*c.productVariables.Platform_sdk_version)
 }
 
+func (c *config) RawPlatformSdkVersion() *int {
+	return c.productVariables.Platform_sdk_version
+}
+
 func (c *config) PlatformSdkFinal() bool {
 	return Bool(c.productVariables.Platform_sdk_final)
 }