Check UseRBE is set before replacing any template with the RE version.

Test: presubmit
Change-Id: I6df58b4e700f0d231367af2710672d731d20a736
diff --git a/java/dex.go b/java/dex.go
index c85914c..15b4431 100644
--- a/java/dex.go
+++ b/java/dex.go
@@ -288,7 +288,7 @@
 			"outUsageZip": proguardUsageZip.String(),
 			"outDir":      outDir.String(),
 		}
-		if ctx.Config().IsEnvTrue("RBE_R8") {
+		if ctx.Config().UseRBE() && ctx.Config().IsEnvTrue("RBE_R8") {
 			rule = r8RE
 			args["implicits"] = strings.Join(r8Deps.Strings(), ",")
 		}
@@ -304,7 +304,7 @@
 	} else {
 		d8Flags, d8Deps := d8Flags(flags)
 		rule := d8
-		if ctx.Config().IsEnvTrue("RBE_D8") {
+		if ctx.Config().UseRBE() && ctx.Config().IsEnvTrue("RBE_D8") {
 			rule = d8RE
 		}
 		ctx.Build(pctx, android.BuildParams{