Ensure APEX's Java deps use stable SDKs.

Test: m
Bug: 153333044
Change-Id: Ib1acf3073e96fe23c92d292ec0b1a91e2cd408db
diff --git a/java/java.go b/java/java.go
index 38f485e..6739f69 100644
--- a/java/java.go
+++ b/java/java.go
@@ -86,6 +86,14 @@
 	ctx.RegisterSingletonType("kythe_java_extract", kytheExtractJavaFactory)
 }
 
+func (j *Module) CheckStableSdkVersion() error {
+	sdkVersion := j.sdkVersion()
+	if sdkVersion.stable() {
+		return nil
+	}
+	return fmt.Errorf("non stable SDK %v", sdkVersion)
+}
+
 func (j *Module) checkSdkVersions(ctx android.ModuleContext) {
 	if j.SocSpecific() || j.DeviceSpecific() ||
 		(j.ProductSpecific() && ctx.Config().EnforceProductPartitionInterface()) {