Fix Eclipse project generation
Fix Eclipse project generation

The reversion of 672af400818fd90b6d764d01c7f4036b0a67e54e broke
Eclipse project generation again, so a suffix is added to the
gerrit_plugin output target, and the post-build genrule is used
as the actual plugin output.

Change-Id: Ie05d63bee33be8890183d958c5fbcde8a4fa819d

GerritCodeReview/plugins_gitiles