Factor out jinja2 template to be generic

This lets us reuse it for many more config setups to avoid duplication.

Change-Id: I9e77e55d460edb3f8037ce164818e45b6ab7a56e
diff --git a/tools/build_rules/BUILD b/tools/build_rules/BUILD
index f96fb3a..8ad7018 100644
--- a/tools/build_rules/BUILD
+++ b/tools/build_rules/BUILD
@@ -3,3 +3,10 @@
     srcs = ["quiet_success.sh"],
     visibility = ["//visibility:public"],
 )
+
+py_binary(
+    name = "jinja2_generator",
+    srcs = ["jinja2_generator.py"],
+    visibility = ["//visibility:public"],
+    deps = ["@python_jinja2"],
+)