You could try customReportContent
, per https://github.com/ACRA/acra/wiki/AdvancedUsage#wiki-Choosing_which_fields_to_be_included_in_reports. According to the docs, "Only fields which are set in customReportContent are actually processed".
From their sample code:
@ReportsCrashes(formKey = "xxxxxxxxxxxxxxxx",
customReportContent = { APP_VERSION, ANDROID_VERSION, PHONE_MODEL, CUSTOM_DATA, STACK_TRACE, LOGCAT },
mode = ReportingInteractionMode.TOAST,
resToastText = R.string.crash_toast_text)