Remove sdk.proto copy in derive_sdk dir

Make a separate dir for proto files and define libraries there.

Also remove some unnecessary options:
- Two were java-specific, and this proto is only used in cpp code
- The package name is not necessary as this proto is internal to this
  module.

Bug: 173188089
Test: presubmit
Change-Id: I1bfd29741898832e776aaf45ccf17eed598be267
diff --git a/derive_sdk/derive_sdk.cpp b/derive_sdk/derive_sdk.cpp
index fb5f1f5..c117120 100644
--- a/derive_sdk/derive_sdk.cpp
+++ b/derive_sdk/derive_sdk.cpp
@@ -29,9 +29,7 @@
 #include <iostream>
 #include <vector>
 
-#include "packages/modules/SdkExtensions/derive_sdk/sdk.pb.h"
-
-using com::android::sdkext::proto::SdkVersion;
+#include "packages/modules/SdkExtensions/proto/sdk.pb.h"
 
 namespace android {
 namespace derivesdk {