validate: reporter only abort with GST_VALIDATE_REPORTER_REPORT
In other words, no abort when GST_VALIDATE_REPORTER_KEEP.
When GST_VALIDATE_REPORTER_KEEP, gst_validate_runner_add_report is not called, and inside that function is where the logic to check if expected is executed.
Without this change, issues reported as expected-issue can abort the execution if the report is kept by the reporter but not reported to the runner (GST_VALIDATE_REPORTER_KEEP).
I found this bug with a legacy decoder and a video that changes resolutions several times. When changing resolutions _find_master_report_for_sink_pad returns TRUE.