Prepare cargo_embargo.json for multi-variants am: 69cdbdb960 am: 3c4d2cde4f

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/memoffset/+/2952667

Change-Id: Ieac26ae38cea12c6588f89169d5567d836a99bff
Signed-off-by: Automerger Merge Worker <[email protected]>
diff --git a/cargo_embargo.json b/cargo_embargo.json
index 87c3870..c458c58 100644
--- a/cargo_embargo.json
+++ b/cargo_embargo.json
@@ -1,5 +1,4 @@
 {
-  "min_sdk_version": "29",
   "package": {
     "memoffset": {
       "dep_blocklist": [
@@ -7,5 +6,10 @@
       ]
     }
   },
-  "tests": true
+  "variants": [
+    {
+      "min_sdk_version": "29",
+      "tests": true
+    }
+  ]
 }