Guarantee frameworks.aidl stability.

Apps share these classes from the BCP, so even if
they are changed, they stay in sync.

Bug: 258850063
Test: build
Change-Id: I50b6a928c29f5d9eca9496b91363a8fc5d397b00
diff --git a/java/sdk.go b/java/sdk.go
index 4ef4ee2..b8ea067 100644
--- a/java/sdk.go
+++ b/java/sdk.go
@@ -308,10 +308,12 @@
 
 			rule.Command().
 				Text("rm -f").Output(aidl)
+
 			rule.Command().
 				BuiltTool("sdkparcelables").
 				Input(jar).
-				Output(aidl)
+				Output(aidl).
+				Flag("--guarantee_stable")
 
 			aidls = append(aidls, aidl)
 		}