* stable-3.1:
Update webhooks plugin to latest master revision
Delete unused download command general preference
Remove theme preferences
Remove key_map_type edit preference
Update description of git_basic_auth_policy field in AuthInfo
Delete unused GroupDetail and GroupInfo classes
Delete unused JdbcUtil class
Schema_181: Fix typo in UI message
Fix wrong javadoc tags
Update git submodules
Documentation: Fix java SDK typo in dev-eclipse.txt
Upgrade jackson-core to 2.10.2
Fix failures on performance.measure with undefined mark name
Reduce change spamming from CI
Link checker result to the proper console URL
Remove unused createCheckPayload() method
Bazel: Force sourcemaps inlining in polymer bundler
Change-Id: Id3aaf78c88434d8878a56813ddc753044ba19881