Merge branch 'stable-2.14'

* stable-2.14:
  CacheEvictionIT: Re-enable and adapt to use @GlobalPluginConfig
  Migrate plugin config to own configuration file
  Disallow DELETE when index does not support delete
  Factor common code out of Index*RestApiServlet classes
  Forward group indexing event
  Index{Account,Change}RestApiServlet: Use UTF_8 constant
  Revert "Ignore flaky CacheEvictionIT"
  Ignore flaky CacheEvictionIT
  IndexAccountRestApiServlet: Remove unnecessary semicolon

Change-Id: If56525eae31484d17cf59b2eb0ff324b7e8524be