[fuchsia] Enable media_unittests to work with run_test_component

This makes the test pass when run by `run-test-component`.
Previously it would only pass when run by `run`.

The manifest being used before was
build/config/fuchsia/tests-with-exec.cmx

Bug: 1118202
Change-Id: I7993cced15856f1f8094fbcd30d733450a364368
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2373404
Commit-Queue: Gary Miguel <garymm@google.com>
Reviewed-by: Xiaohan Wang <xhwang@chromium.org>
Auto-Submit: Gary Miguel <garymm@google.com>
Cr-Commit-Position: refs/heads/master@{#802803}

media/BUILD.gn

@@ -182,6 +182,7 @@ test("media_unittests") {
 
   if (is_fuchsia) {
     deps += [ "//media/fuchsia/audio:unittests" ]
+    manifest = "//media/fuchsia/media_unittests.cmx"
   }
 
   if (enable_media_remoting) {

media/fuchsia/OWNERS

 sergeyu@chromium.org
 yucliu@chromium.org
 wez@chromium.org
+
+per-file *.cmx=set noparent
+per-file *.cmx=file://fuchsia/SECURITY_OWNERS

media/fuchsia/media_unittests.cmx

+{
+  "facets": {
+    "fuchsia.test": {
+      "injected-services": {
+        "fuchsia.intl.PropertyProvider": "fuchsia-pkg://fuchsia.com/intl_property_manager#meta/intl_property_manager.cmx",
+        "fuchsia.media.Audio": "fuchsia-pkg://fuchsia.com/audio#meta/audio.cmx",
+        "fuchsia.mediacodec.CodecFactory": "fuchsia-pkg://fuchsia.com/codec_factory#meta/codec_factory.cmx"
+      },
+      "system-services": [
+        "fuchsia.sysmem.Allocator",
+        "fuchsia.media.AudioCore"
+      ]
+    }
+  },
+  "sandbox": {
+    "features": [
+      "config-data",
+      "deprecated-ambient-replace-as-executable",
+      "isolated-persistent-storage",
+      "isolated-temp",
+      "vulkan"
+    ],
+    "dev": [
+      "null",
+      "zero"
+    ],
+    "services": [
+      "fuchsia.camera3.DeviceWatcher",
+      "fuchsia.intl.PropertyProvider",
+      "fuchsia.logger.Log",
+      "fuchsia.logger.LogSink",
+      "fuchsia.media.Audio",
+      "fuchsia.media.SessionAudioConsumerFactory",
+      "fuchsia.media.drm.Widevine",
+      "fuchsia.mediacodec.CodecFactory",
+      "fuchsia.memorypressure.Provider",
+      "fuchsia.process.Launcher",
+      "fuchsia.sys.Loader",
+      "fuchsia.sysmem.Allocator"
+    ]
+  }
+}