Add java.lang.ref classes into EXPECTED_UPSTREAM

The libcore-compare-upstreams tool is used to guess the version of each
file by comparing the diff.

Bug: 111603149
Test: ojluni_refresh_files
Change-Id: I4c75c02aa00f6a0e8a083221befebf758cfc560c
1 file changed
tree: 6a007c681014fcbb89f573f9653f847b85149765
  1. ojluni/
  2. tools/
  3. EXPECTED_UPSTREAM