pw_blob_store: Add keir to OWNERS

So that we have a Pigweed core team member among owners.

Change-Id: Ie155256a32f2de6e650b2c33e42982aef56433d7
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/127045
Commit-Queue: Ted Pudlik <tpudlik@google.com>
Reviewed-by: Chad Norvell <chadnorvell@google.com>
diff --git a/pw_blob_store/OWNERS b/pw_blob_store/OWNERS
index 0ed2d4b..892ad93 100644
--- a/pw_blob_store/OWNERS
+++ b/pw_blob_store/OWNERS
@@ -1,2 +1,3 @@
 davidrogers@google.com
 ewout@google.com
+keir@google.com