libcore: update OWNERS

Update team members.

Mark some approvers as last resort (see go/android-codereviews).

Comment out preferred default reviewer as syntax not supported by
checkowners.py nor respected by gerrit.

Bug: N/A
Test: build/make/tools/checkowners.py -c libcore/OWNERS
Change-Id: I9459701283acbf1274ae304faf512717f41d911b
diff --git a/OWNERS b/OWNERS
index 2f5b841..234b99e 100644
--- a/OWNERS
+++ b/OWNERS
@@ -1,22 +1,28 @@
 # Bug component: 24949
 
-# Use this reviewer by default.
-android-libcore-team+review@google.com
+# Ideally, we would use this reviewer by default, but gerrit and
+# checkowners.py do not recognize email subaddresses:
+# android-libcore-team+review@google.com
 
 # People who can approve changes for submission; don't send review emails to them
 # unless you know what you're doing.
 miguelaranda@google.com
 mingaleev@google.com
-nfuller@google.com
 nikitai@google.com
 oth@google.com
-paulduffin@google.com
 prb@google.com
-rpl@google.com
+skvadrik@google.com
+sorinbasca@google.com
 vichang@google.com
 
+# Emeritus libcore team members; don't send review emails to them
+# unless you are in the libcore team.
+nfuller@google.com #{LAST_RESORT_SUGGESTION}
+paulduffin@google.com #{LAST_RESORT_SUGGESTION}
+
 # Don't send these folks any review emails for this project.
-calin@google.com
-narayan@google.com
-ngeoffray@google.com
-vmarko@google.com
+hboehm@google.com #{LAST_RESORT_SUGGESTION}
+narayan@google.com #{LAST_RESORT_SUGGESTION}
+ngeoffray@google.com #{LAST_RESORT_SUGGESTION}
+rpl@google.com #{LAST_RESORT_SUGGESTION}
+vmarko@google.com #{LAST_RESORT_SUGGESTION}