message: Do not make invalid config with only NDK/SDK configured
diff: @@ -45,7 +45,7 @@ def _android_autoconf_impl(repository_ctx):
  ndk_home = repository_ctx.os.environ.get(_ANDROID_NDK_HOME)
  ndk_api_level = repository_ctx.os.environ.get(_ANDROID_NDK_API_VERSION)
  - sdk_rule = "pass"
  + sdk_rule = ""
  if all([sdk_home, sdk_api_level, build_tools_version]):
  sdk_rule = _ANDROID_SDK_REPO_TEMPLATE % (
  sdk_home,
  @@ -53,10 +53,13 @@ def _android_autoconf_impl(repository_ctx):
  build_tools_version,
  )
  - ndk_rule = "pass"
  + ndk_rule = ""
  if all([ndk_home, ndk_api_level]):
  ndk_rule = _ANDROID_NDK_REPO_TEMPLATE % (ndk_home, ndk_api_level)
  + if ndk_rule == "" and sdk_rule == "":
  + sdk_rule = "pass"
  +
  repository_ctx.template(
  "BUILD",
  Label("//third_party/android:android_configure.BUILD.tpl"),
  