DVCS bitbucket cloud pull request endpoint fails to parse

Issue Summary

Caused by: java.lang.UnsupportedOperationException: JsonObjectCaused by: java.lang.UnsupportedOperationException: JsonObject at com.google.gson.JsonElement.getAsString(JsonElement.java:191) at com.atlassian.jira.plugins.dvcs.spi.bitbucket.clientlibrary.model.repository.pullrequest.BitbucketPullRequestActivityEnvelopeDeserializer.deserialize(BitbucketPullRequestActivityEnvelopeDeserializer.java:46)

java.lang.UnsupportedOperationException: JsonObject is thrown by BitbucketPullRequestActivityEnvelopeDeserializer when it fails to deserialize the pull request endpoint payload:

https://developer.atlassian.com/bitbucket/api/2/reference/resource/repositories/%7Bworkspace%7D/%7Brepo_slug%7D/pullrequests/activity

It parses the "pull_request" object and then attempts to find either one of the following json objects: "comment", "approval", or "update".

If it fails to find either of these json objects then it throws the above exception.

Replication steps

• Create a Pull Request with an approver
• Approver sets status to 'Changes Requested'
• DVCS syncs Pull Request

Expected Result

DVCS ignores pull request activity type for `changes_requested`

Actual result

DVCS fails with pull request activity type for `changes_requested`

Workaround

None yet

Suggested Fix

Handle missing data correctly rather than throwing an exception.

Also suggest we add more logging to diagnose the potential source of the issue as currently we can't tell what the contents of the payload from Bitbucket is.