aidl: -ninja -> --ninja

Bug: 110967839
Test: AIDL's runtests.sh
Change-Id: I49c0a2526b6d4083c927104a3e66017080000847
diff --git a/cc/gen.go b/cc/gen.go
index c794f5c..487f662 100644
--- a/cc/gen.go
+++ b/cc/gen.go
@@ -48,7 +48,7 @@
 
 	aidl = pctx.AndroidStaticRule("aidl",
 		blueprint.RuleParams{
-			Command:     "$aidlCmd -d${out}.d -ninja $aidlFlags $in $outDir $out",
+			Command:     "$aidlCmd -d${out}.d --ninja $aidlFlags $in $outDir $out",
 			CommandDeps: []string{"$aidlCmd"},
 			Depfile:     "${out}.d",
 			Deps:        blueprint.DepsGCC,