Fix external build issue

media_cas_packager_sdk/public/BUILD

@@ -22,6 +22,7 @@ filegroup(
     name = "binary_release_files",
     srcs = glob(["*.h"]) + [
         ":wv_ecmg",
+        ":wv_emmg",
         "wv_cas_curl_key_fetcher.cc",
         "wv_cas_types.cc",
     ],
@@ -46,7 +47,6 @@ cc_library(
         "//base",
         "@abseil_repo//absl/base:core_headers",
         "//common:status",
-        "//media_cas_packager_sdk/internal:ecm",
         "//protos/public:media_cas_cc_proto",
         "//protos/public:media_cas_encryption_cc_proto",
     ],
@@ -116,12 +116,9 @@ cc_test(
 
 cc_library(
     name = "wv_cas_key_fetcher",
-    srcs = [
-        "wv_cas_key_fetcher.cc",
-    ],
-    hdrs = [
-        "wv_cas_key_fetcher.h",
-    ],
+    srcs = ["wv_cas_key_fetcher.cc"],
+    hdrs = ["wv_cas_key_fetcher.h"],
+    copts = PUBLIC_COPTS,
     deps = [
         ":wv_cas_types",
         "//base",
@@ -131,6 +128,9 @@ cc_library(
         "//common:status",
         "//protos/public:media_cas_encryption_cc_proto",
     ],
+    # Make sure libmedia_cas_packager_sdk links in symbols defined in this
+    # target.
+    alwayslink = 1,
 )
 
 cc_test(