[incremental] native implementation of Incremental Service

The implementation of IIncrementalManager.aidl. TODO to refactor this.

Test: atest service.incremental_test
Change-Id: Ib8c8a9c0e7f0289b4bcd8961fa39746ed12b4310
diff --git a/services/incremental/Metadata.proto b/services/incremental/Metadata.proto
new file mode 100644
index 0000000..0ff3c32
--- /dev/null
+++ b/services/incremental/Metadata.proto
@@ -0,0 +1,23 @@
+syntax = "proto3";
+
+package android.incremental.metadata;
+
+message BindPoint {
+    int32 storage_id = 1;
+    string source_subdir = 2;
+    string dest_path = 3;
+}
+
+message DataLoader {
+    string package_name = 1;
+    string arguments = 2;
+}
+
+message Storage {
+    int32 id = 1;
+}
+
+message Mount {
+    Storage storage = 1;
+    DataLoader loader = 2;
+}