message: upstream: fix typo (s/lb_type/lb_policy/g) in previous commit.
  While there, change to uppercase letters to match v2 style.
  *Risk Level*: n/a
  *Testing*: bazel test //test/...
  *Docs Changes*: n/a
  *Release Notes*: n/a
diff: @@ -488,8 +488,8 @@ TEST_F(OriginalDstClusterTest, UseHttpHeaderEnabled) {
  std::string yaml = R"EOF(
  name: "name"
  connect_timeout: 1.250s
  - type: original_dst
  - lb_type: original_dst_lb
  + type: ORIGINAL_DST
  + lb_policy: ORIGINAL_DST_LB
  original_dst_lb_config:
  use_http_header: true
  )EOF";
  @@ -562,8 +562,8 @@ TEST_F(OriginalDstClusterTest, UseHttpHeaderDisabled) {
  std::string yaml = R"EOF(
  name: "name"
  connect_timeout: 1.250s
  - type: original_dst
  - lb_type: original_dst_lb
  + type: ORIGINAL_DST
  + lb_policy: ORIGINAL_DST_LB
  )EOF";
  EXPECT_CALL(initialized_, ready());
  