[sdk] Reordering a couple json variables so that they appear alphabetically.

This addresses an unresolved comment from a previous review -- it totally skipped my mind in the previous review, sorry about that.

http://fxr/276835

Bug: DX-537

Change-Id: Ia9b9bdcda7d7256f24e002161657d6868c32a3fc
diff --git a/build/sdk/meta/cc_prebuilt_library.json b/build/sdk/meta/cc_prebuilt_library.json
index 72624b5..41b7dc0 100644
--- a/build/sdk/meta/cc_prebuilt_library.json
+++ b/build/sdk/meta/cc_prebuilt_library.json
@@ -78,10 +78,10 @@
       "required": [
         "binaries",
         "deps",
+        "dist_dir",
         "format",
         "headers",
         "include_dir",
-        "dist_dir",
         "root",
 
         "name",