Generate getters/setters for subtree_is_sticky.

Currently, the subtree_is_sticky field is 'storage_only', so
it has no generated public getters/setters. This patch changes it to a
'primitive' field so that its getters/setters can be generated as well.

Diff of generated files:
https://gist.github.com/darrnshn/27b4a61fe64a79395888bf7f2b973fe0/revisions

BUG=628043

Review-Url: https://codereview.chromium.org/2897893002
Cr-Commit-Position: refs/heads/master@{#474586}
2 files changed