media: Enable EncryptedMediaHdcpPolicyCheck by default

- Remove the origin trial
- Mark the status as "stable"

Blink intent-to-ship approval at
https://groups.google.com/a/chromium.org/d/msg/blink-dev/w0jNaAhyTV0/3oDkR_ASAQAJ

TBR=timvolodine

Bug: 709348
Test: Manually tested to make sure the API is available by default.
Change-Id: I84306dc0e17f104043fa2205529e650e255e7175
Reviewed-on: https://chromium-review.googlesource.com/c/1423090
Commit-Queue: Xiaohan Wang <xhwang@chromium.org>
Reviewed-by: Philip Jägenstedt <foolip@chromium.org>
Cr-Commit-Position: refs/heads/master@{#625807}

android_webview/tools/system_webview_shell/test/data/webexposed/global-interface-listing-expected.txt

@@ -3620,6 +3620,7 @@ interface MediaKeys
     attribute @@toStringTag
     method constructor
     method createSession
+    method getStatusForPolicy
     method setServerCertificate
 interface MediaList
     attribute @@toStringTag

third_party/blink/renderer/modules/encryptedmedia/media_keys_get_status_for_policy.idl

@@ -6,7 +6,6 @@
 
 [
     ImplementedAs=MediaKeysGetStatusForPolicy,
-    OriginTrialEnabled=EncryptedMediaHdcpPolicyCheck,
     SecureContext
 ] partial interface MediaKeys {
     [Measure, CallWith=ScriptState] Promise<MediaKeyStatus> getStatusForPolicy(MediaKeysPolicy policy);

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -421,8 +421,7 @@
     },
     {
       name: "EncryptedMediaHdcpPolicyCheck",
-      origin_trial_feature_name: "EncryptedMediaHdcpPolicyCheck",
-      status: "experimental",
+      status: "stable",
     },
     {
       name: "EncryptedMediaPersistentUsageRecordSession",

third_party/blink/web_tests/virtual/stable/webexposed/global-interface-listing-expected.txt

@@ -3816,6 +3816,7 @@ interface MediaKeys
     attribute @@toStringTag
     method constructor
     method createSession
+    method getStatusForPolicy
     method setServerCertificate
 interface MediaList
     attribute @@toStringTag