Add system_$(VER)

The system_$(VER) is added for vendor, similar to sdk.

Bug: 67724799
Test: build
Merged-In: I2545c92707591ca278066870c74e9f49e9825855
Change-Id: I2545c92707591ca278066870c74e9f49e9825855
(cherry picked from commit b8baff1fa3)

android/util.go

@@ -157,3 +157,10 @@ func callerName(skip int) (pkgPath, funcName string, ok bool) {
 	ok = true
 	return
 }
+
+func GetNumericSdkVersion(v string) string {
+	if strings.Contains(v, "system_") {
+		return strings.Replace(v, "system_", "", 1)
+	}
+	return v
+}