Enable "gn check" for //third_party/blink/renderer/modules/media_capabilities

This CL fixes the following four errors:

================================================================
ERROR at //third_party/blink/renderer/modules/media_capabilities/media_capabilities.cc:52:11: Include not allowed.
          ^------------------------------------------------------------------------
...
___________________
ERROR at //third_party/blink/renderer/modules/media_capabilities/media_capabilities.cc:53:11: Include not allowed.
          ^--------------------------------------------------------------------------
...
___________________
ERROR at //third_party/blink/renderer/modules/media_capabilities/media_capabilities.cc:54:11: Include not allowed.
          ^-------------------------------------------------------------------------------------------
...
___________________
ERROR at //third_party/blink/renderer/modules/media_capabilities/media_capabilities.cc:55:11: Include not allowed.
          ^------------------------------------------------------------------------
...
================================================================

This CL has no behavior changes.

Bug: 800764
Change-Id: I420c3a1b758f08f8011d1cdc43ba66390ecd14ef
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2400409
Commit-Queue: Kent Tamura <tkent@chromium.org>
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Auto-Submit: Kent Tamura <tkent@chromium.org>
Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
Cr-Commit-Position: refs/heads/master@{#805639}

.gn

@@ -253,7 +253,6 @@ no_check_targets = [
   "//third_party/blink/renderer/core:*",  # 823 errors
   "//third_party/blink/renderer/modules/canvas:*",  # 1 error
   "//third_party/blink/renderer/modules/font_access:*",  # 3 errors
-  "//third_party/blink/renderer/modules/media_capabilities:*",  # 5 errors
   "//third_party/blink/renderer/modules/peerconnection:*",  # 43 errors
   "//third_party/blink/renderer/modules/webtransport:*",  # 16 errors
   "//third_party/blink/renderer/modules:*",  # 321 errors

third_party/blink/renderer/modules/media_capabilities/BUILD.gn

@@ -18,6 +18,7 @@ blink_modules_sources("media_capabilities") {
   deps = [
     "//media",
     "//media/learning/mojo:impl",
+    "//third_party/blink/renderer/modules/encryptedmedia:encryptedmedia",
     "//third_party/blink/renderer/modules/mediarecorder",
   ]
 }