Merge branch 'stable-2.15' into stable-2.16 * stable-2.15: Upgrade bazlets to latest stable-2.15 to build with 2.15.19 API Upgrade bazlets to latest stable-2.14 to build with 2.14.21 API Change-Id: I8350fc1b587740f9b096b3409c381cbc7927f05a