Add libgkiprops.

This is the sysprop API for GKI related properties.
Test: builds
Bug: 162623577

Change-Id: Id14ecf9cf6a389a5425ba61b1aa2620b220d3c5d
diff --git a/sysprop/Android.bp b/sysprop/Android.bp
new file mode 100644
index 0000000..b2d0e20
--- /dev/null
+++ b/sysprop/Android.bp
@@ -0,0 +1,27 @@
+//
+// Copyright (C) 2020 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+sysprop_library {
+    name: "gkiprops",
+    property_owner: "Platform",
+    recovery_available: true,
+    srcs: [
+        "android/sysprop/GkiProperties.sysprop",
+    ],
+    api_packages: [
+        "android.sysprop",
+    ],
+}
diff --git a/sysprop/android/sysprop/GkiProperties.sysprop b/sysprop/android/sysprop/GkiProperties.sysprop
new file mode 100644
index 0000000..e99026f
--- /dev/null
+++ b/sysprop/android/sysprop/GkiProperties.sysprop
@@ -0,0 +1,31 @@
+# Copyright (C) 2020 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+owner: Platform
+module: "android.sysprop.GkiProperties"
+prop {
+    api_name: "prevent_downgrade_version"
+    type: Boolean
+    prop_name: "ro.build.ab_update.gki.prevent_downgrade_version"
+    scope: Internal
+    access: Readonly
+}
+
+prop {
+    api_name: "prevent_downgrade_spl"
+    type: Boolean
+    prop_name: "ro.build.ab_update.gki.prevent_downgrade_spl"
+    scope: Internal
+    access: Readonly
+}
diff --git a/sysprop/api/gkiprops-current.txt b/sysprop/api/gkiprops-current.txt
new file mode 100644
index 0000000..38edfea
--- /dev/null
+++ b/sysprop/api/gkiprops-current.txt
@@ -0,0 +1,13 @@
+props {
+  module: "android.sysprop.GkiProperties"
+  prop {
+    api_name: "prevent_downgrade_spl"
+    scope: Internal
+    prop_name: "ro.build.ab_update.gki.prevent_downgrade_spl"
+  }
+  prop {
+    api_name: "prevent_downgrade_version"
+    scope: Internal
+    prop_name: "ro.build.ab_update.gki.prevent_downgrade_version"
+  }
+}
diff --git a/sysprop/api/gkiprops-latest.txt b/sysprop/api/gkiprops-latest.txt
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/sysprop/api/gkiprops-latest.txt