Add User* OWNERS file (part 1)

Two parts are required due to b/175318571.

Test: N/A
Change-Id: I2bd2e1f71490e0d006ceeea177e2e5d5cd520a9a
diff --git a/MULTIUSER_OWNERS b/MULTIUSER_OWNERS
new file mode 100644
index 0000000..fbc611a
--- /dev/null
+++ b/MULTIUSER_OWNERS
@@ -0,0 +1,4 @@
+# OWNERS of Multiuser related files
+bookatz@google.com
+omakoto@google.com
+yamasani@google.com