Move RingBuffer to SystemUICommon.

This change adds a new module SystemUICommon and moves RingBuffer to
it. This is to prepare introducing a new logging library which would
depend on it.

Bug: 276475093
Test: RingBuffer does not have existing tests, so just verified
LogBuffer works correctly on device

Change-Id: Ib71fcf8526021be1ac3fe279210c54cb7d4cd0e6
diff --git a/packages/SystemUI/common/Android.bp b/packages/SystemUI/common/Android.bp
new file mode 100644
index 0000000..e36ada8
--- /dev/null
+++ b/packages/SystemUI/common/Android.bp
@@ -0,0 +1,39 @@
+// Copyright (C) 2023 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.
+
+package {
+    // See: http://go/android-license-faq
+    // A large-scale-change added 'default_applicable_licenses' to import
+    // all of the 'license_kinds' from "frameworks_base_packages_SystemUI_license"
+    // to get the below license kinds:
+    //   SPDX-license-identifier-Apache-2.0
+    default_applicable_licenses: ["frameworks_base_packages_SystemUI_license"],
+}
+
+android_library {
+
+    name: "SystemUICommon",
+
+    srcs: [
+        "src/**/*.java",
+        "src/**/*.kt",
+    ],
+
+    static_libs: [
+        "androidx.core_core-ktx",
+    ],
+
+    manifest: "AndroidManifest.xml",
+    kotlincflags: ["-Xjvm-default=all"],
+}