RFR: 1727: Ability to control whether clean backports require review [v2]

[Zhao Song]

> In this patch, PR bot has been added with the capability to control the requirement of reviews for clean backports. 
> 
> By default, no review is necessary for clean backports. 
> 
> However, if it is desired to enable the requirement of reviews for backports in a repo, the configuration can be added to the PR bot configuration as follows:
> 
> {
>   "pr": {
>       "repositories": {
>           "repo1": {
>                "requiresReviewForBackport": true
>           }
>        }
>   }
> }

Zhao Song has updated the pull request incrementally with one additional commit since the last revision:

  renamed two variables

-------------

Changes:
  - all: https://git.openjdk.org/skara/pull/1457/files
  - new: https://git.openjdk.org/skara/pull/1457/files/1a3386b1..8f1719ef

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=skara&pr=1457&range=01
 - incr: https://webrevs.openjdk.org/?repo=skara&pr=1457&range=00-01

  Stats: 28 lines in 7 files changed: 0 ins; 0 del; 28 mod
  Patch: https://git.openjdk.org/skara/pull/1457.diff
  Fetch: git fetch https://git.openjdk.org/skara pull/1457/head:pull/1457

PR: https://git.openjdk.org/skara/pull/1457