Refactor RBE support for Javac/R8/D8 to use the remoteexec package.

Test: build with and without RBE_JAVAC/RBE_R8/RBE_D8 set.
Change-Id: I1607f8cfb4d2c3cbb3672152bbeb561d9968bc60
diff --git a/cc/config/global.go b/cc/config/global.go
index 39c4c33..f9255be 100644
--- a/cc/config/global.go
+++ b/cc/config/global.go
@@ -257,10 +257,10 @@
 		return ""
 	})
 
-	pctx.VariableFunc("RECXXPool", envOverrideFunc("RBE_CXX_POOL", remoteexec.DefaultPool))
-	pctx.VariableFunc("RECXXLinksPool", envOverrideFunc("RBE_CXX_LINKS_POOL", remoteexec.DefaultPool))
-	pctx.VariableFunc("RECXXLinksExecStrategy", envOverrideFunc("RBE_CXX_LINKS_EXEC_STRATEGY", remoteexec.LocalExecStrategy))
-	pctx.VariableFunc("REAbiDumperExecStrategy", envOverrideFunc("RBE_ABI_DUMPER_EXEC_STRATEGY", remoteexec.LocalExecStrategy))
+	pctx.VariableFunc("RECXXPool", remoteexec.EnvOverrideFunc("RBE_CXX_POOL", remoteexec.DefaultPool))
+	pctx.VariableFunc("RECXXLinksPool", remoteexec.EnvOverrideFunc("RBE_CXX_LINKS_POOL", remoteexec.DefaultPool))
+	pctx.VariableFunc("RECXXLinksExecStrategy", remoteexec.EnvOverrideFunc("RBE_CXX_LINKS_EXEC_STRATEGY", remoteexec.LocalExecStrategy))
+	pctx.VariableFunc("REAbiDumperExecStrategy", remoteexec.EnvOverrideFunc("RBE_ABI_DUMPER_EXEC_STRATEGY", remoteexec.LocalExecStrategy))
 }
 
 var HostPrebuiltTag = pctx.VariableConfigMethod("HostPrebuiltTag", android.Config.PrebuiltOS)