Removed unused Import sync_enums.proto

Bug: 1027246
Change-Id: Ia5f47b53b502dc98ef65d4f65f9e933ab73b2330
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1928204Reviewed-by: Markus Heintz <markusheintz@chromium.org>
Commit-Queue: Sky Malice <skym@chromium.org>
Cr-Commit-Position: refs/heads/master@{#721086}

components/sync/protocol/user_consent_specifics.proto

@@ -16,7 +16,6 @@ option optimize_for = LITE_RUNTIME;
 
 package sync_pb;
 
-import "sync_enums.proto";
 import "user_consent_types.proto";
 
 // Next id: 14