Add default active developers into OWNERS

Bug: 33166666
Test: gerrit uploader
Change-Id: I17ea3d083db2730a19b14dd063c5a88c286802d8
diff --git a/OWNERS b/OWNERS
new file mode 100644
index 0000000..1ca4de7
--- /dev/null
+++ b/OWNERS
@@ -0,0 +1,6 @@
+# Default owners are top 3 active developers of the past 1 or 2 years
+# or people with more than 10 commits last year.
+# Please update this list if you find better owner candidates.
+jiyong@google.com
+chh@google.com
+justinyun@google.com