update_engine: Remove check for deprecated values

Build gives warning for these deprecated values in protobuf. We don't
need to test for the existence of these fields anyway because if they
exist, we just ignore them.

BUG=chromium:163075733
TEST=None

Change-Id: I6e39a521c39d6398ca096cc43219aaef7bd628de
Reviewed-on: https://chromium-review.googlesource.com/c/aosp/platform/system/update_engine/+/2357491
Tested-by: Amin Hassani <ahassani@chromium.org>
Reviewed-by: Jae Hoon Kim <kimjae@chromium.org>

payload_consumer/delta_performer.cc

diff --git a/payload_consumer/delta_performer.cc b/payload_consumer/delta_performer.cc
index 11cf006..95dfbcc 100644
--- a/payload_consumer/delta_performer.cc
+++ b/payload_consumer/delta_performer.cc
@@ -1475,14 +1475,6 @@
     }
   }
 
-  if (manifest_.has_old_rootfs_info() || manifest_.has_new_rootfs_info() ||
-      manifest_.has_old_kernel_info() || manifest_.has_new_kernel_info() ||
-      manifest_.install_operations_size() != 0 ||
-      manifest_.kernel_install_operations_size() != 0) {
-    LOG(ERROR) << "Manifest contains deprecated fields.";
-    return ErrorCode::kPayloadMismatchedType;
-  }
-
   if (manifest_.max_timestamp() < hardware_->GetBuildTimestamp()) {
     LOG(ERROR) << "The current OS build timestamp ("
                << hardware_->GetBuildTimestamp()