Vendor apexes can be "updatable: true"

Vendor APEXes can be updatable unless it sets "use_vndk_as_stable:true".
When "updatable:true", it should meet the "updatable" requirements like
"should set min_sdk_version".

Bug: 274396342
Bug: 274041915
Test: m nothing (soong tests)
Change-Id: I746d8941c21e883c1eba3e1f1e5a414a67db071a
diff --git a/apex/apex.go b/apex/apex.go
index b2ca6c4..4424b22 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -3025,8 +3025,8 @@
 		if a.UsePlatformApis() {
 			ctx.PropertyErrorf("updatable", "updatable APEXes can't use platform APIs")
 		}
-		if a.SocSpecific() || a.DeviceSpecific() {
-			ctx.PropertyErrorf("updatable", "vendor APEXes are not updatable")
+		if proptools.Bool(a.properties.Use_vndk_as_stable) {
+			ctx.PropertyErrorf("use_vndk_as_stable", "updatable APEXes can't use external VNDK libs")
 		}
 		if a.FutureUpdatable() {
 			ctx.PropertyErrorf("future_updatable", "Already updatable. Remove `future_updatable: true:`")