Add schema for task profiles

- Add proto3 files as schema for JSON task profiles / cgroups
  files.

- Add tests to ensure the JSON files (on the device) conforms
  the schema. (libprocessgroup_proto_test)

Test: libprocessgroup_proto_test

Bug: 123664216
Change-Id: I1cab73bd0d3852ff8827fee0be22373da8a6fc5b
diff --git a/libprocessgroup/profiles/cgroups.proto b/libprocessgroup/profiles/cgroups.proto
new file mode 100644
index 0000000..f4070c5
--- /dev/null
+++ b/libprocessgroup/profiles/cgroups.proto
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+syntax = "proto3";
+
+package android.profiles;
+
+// Next: 3
+message Cgroups {
+    repeated Cgroup cgroups = 1 [json_name = "Cgroups"];
+    Cgroups2 cgroups2 = 2 [json_name = "Cgroups2"];
+}
+
+// Next: 6
+message Cgroup {
+    string controller = 1 [json_name = "Controller"];
+    string path = 2 [json_name = "Path"];
+    string mode = 3 [json_name = "Mode"];
+    string uid = 4 [json_name = "UID"];
+    string gid = 5 [json_name = "GID"];
+}
+
+// Next: 5
+message Cgroups2 {
+    string path = 1 [json_name = "Path"];
+    string mode = 2 [json_name = "Mode"];
+    string uid = 3 [json_name = "UID"];
+    string gid = 4 [json_name = "GID"];
+}