Add x86_host vars to config.bzl

Test: USE_BAZEL_ANALYSIS=1 m adbd
Test: Manually verified config.bzl contains various x86_host flags after
bp2build.
Test: Unit tests

Change-Id: Ie9201ea2be4cd1c6659bea088a797cedbae37403
diff --git a/bp2build/conversion.go b/bp2build/conversion.go
index d34a4ba..944cb83 100644
--- a/bp2build/conversion.go
+++ b/bp2build/conversion.go
@@ -17,11 +17,11 @@
 	Contents string
 }
 
-func CreateSoongInjectionFiles(metrics CodegenMetrics) []BazelFile {
+func CreateSoongInjectionFiles(cfg android.Config, metrics CodegenMetrics) []BazelFile {
 	var files []BazelFile
 
 	files = append(files, newFile("cc_toolchain", GeneratedBuildFileName, "")) // Creates a //cc_toolchain package.
-	files = append(files, newFile("cc_toolchain", "constants.bzl", config.BazelCcToolchainVars()))
+	files = append(files, newFile("cc_toolchain", "constants.bzl", config.BazelCcToolchainVars(cfg)))
 
 	files = append(files, newFile("metrics", "converted_modules.txt", strings.Join(metrics.convertedModules, "\n")))