Add webview pinning trunk stable flag

Bug: 307594624
Change-Id: I8eb3c4eb68efe8b1e1706b5e1f5a711fcef82054
diff --git a/AconfigFlags.bp b/AconfigFlags.bp
index 44f3d70..040a869 100644
--- a/AconfigFlags.bp
+++ b/AconfigFlags.bp
@@ -53,6 +53,7 @@
     ":android.app.flags-aconfig-java{.generated_srcjars}",
     ":android.credentials.flags-aconfig-java{.generated_srcjars}",
     ":android.view.contentprotection.flags-aconfig-java{.generated_srcjars}",
+    ":com.android.server.flags.pinner-aconfig-java{.generated_srcjars}",
     ":android.service.voice.flags-aconfig-java{.generated_srcjars}",
     ":android.media.tv.flags-aconfig-java{.generated_srcjars}",
     ":android.service.autofill.flags-aconfig-java{.generated_srcjars}",
@@ -539,6 +540,19 @@
     defaults: ["framework-minus-apex-aconfig-java-defaults"],
 }
 
+// Pinner Service
+aconfig_declarations {
+    name: "com.android.server.flags.pinner-aconfig",
+    package: "com.android.server.flags",
+    srcs: ["services/core/java/com/android/server/flags/pinner.aconfig"],
+}
+
+java_aconfig_library {
+    name: "com.android.server.flags.pinner-aconfig-java",
+    aconfig_declarations: "com.android.server.flags.pinner-aconfig",
+    defaults: ["framework-minus-apex-aconfig-java-defaults"],
+}
+
 // Voice
 aconfig_declarations {
     name: "android.service.voice.flags-aconfig",