Validate PPI face payload metadata

src/assets/ppi_header.h

@@ -54,6 +54,7 @@ struct PpiBodySummary {
     std::uint32_t declared_frame_count = 0;
     std::uint32_t total_layer_frames = 0;
     std::uint32_t dirty_face_count = 0;
+    std::uint32_t rgba_face_payload_count = 0;
     std::uint64_t compressed_face_bytes = 0;
     std::uint32_t info_bytes = 0;
 };