DLPX-96312 Persist InfluxDB bucket IDs in influxdb_meta

delphix-influxdb-init already knows both bucket IDs (it just created
them via /api/v2/setup and /api/v2/buckets). Persist them into
/etc/influxdb/influxdb_meta as INFLUXDB_BUCKET_ID and
INFLUXDB_SUPPORT_BUCKET_ID so callers (support_info, future tooling)
can look up either bucket without having to scan the engine data
directory.

This avoids a class of bugs where a scan-the-data-dir heuristic returns
the wrong bucket on engines that contain more than just default and
support_metrics — notably InfluxDB's internal _monitoring bucket,
which alphabetically sorts ahead of support_metrics by hex bucket ID
on this engine and was being silently substituted in every bundle.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: dbshah12

influxdb/delphix-influxdb-init

@@ -259,7 +259,9 @@ tmp_meta="$(mktemp "${INFLUXDB_META_FILE}.XXXXXX")"
 cat >"$tmp_meta" <<EOF
 INFLUXDB_ORG=$INFLUXDB_ORG
 INFLUXDB_BUCKET=$INFLUXDB_BUCKET
+INFLUXDB_BUCKET_ID=$BUCKET_ID
 INFLUXDB_SUPPORT_BUCKET=$INFLUXDB_SUPPORT_BUCKET
+INFLUXDB_SUPPORT_BUCKET_ID=$SUPPORT_BUCKET_ID
 INFLUXDB_ADMIN_USER=$INFLUXDB_ADMIN_USER
 INFLUXDB_ADMIN_PASSWORD=$INFLUXDB_ADMIN_PASSWORD
 INFLUXDB_WRITE_TOKEN=$WRITE_TOKEN