Add media_support_internal to media_util gn target (#4047)

It was missing.  It didn't cause any build issues as it's a header file.

b/361864042

(cherry picked from commit 08cef06)

starboard/shared/starboard/media/BUILD.gn

@@ -21,6 +21,7 @@ static_library("media_util") {
     "//starboard/shared/starboard/media/codec_util.h",
     "//starboard/shared/starboard/media/key_system_supportability_cache.cc",
     "//starboard/shared/starboard/media/key_system_supportability_cache.h",
+    "//starboard/shared/starboard/media/media_support_internal.h",
     "//starboard/shared/starboard/media/media_util.cc",
     "//starboard/shared/starboard/media/media_util.h",
     "//starboard/shared/starboard/media/mime_supportability_cache.cc",

starboard/stub/BUILD.gn

@@ -115,12 +115,14 @@ static_library("stub_sources") {
     "//starboard/shared/stub/media_get_max_buffer_capacity.cc",
     "//starboard/shared/stub/media_get_progressive_buffer_budget.cc",
     "//starboard/shared/stub/media_get_video_buffer_budget.cc",
-    "//starboard/shared/stub/media_is_audio_supported.cc",
     "//starboard/shared/stub/media_is_buffer_pool_allocate_on_demand.cc",
     "//starboard/shared/stub/media_is_buffer_using_memory_pool.cc",
+<<<<<<< HEAD
     "//starboard/shared/stub/media_is_supported.cc",
     "//starboard/shared/stub/media_is_video_supported.cc",
     "//starboard/shared/stub/media_set_audio_write_duration.cc",
+=======
+>>>>>>> 08cef068d14 (Add media_support_internal to media_util gn target (#4047))
     "//starboard/shared/stub/memory_allocate_aligned_unchecked.cc",
     "//starboard/shared/stub/memory_allocate_unchecked.cc",
     "//starboard/shared/stub/memory_flush.cc",