Update exporters: migration to CharmHub

Also, added kafka_endpoint config to kafka exporter

Change-Id: I24459e33841da33455b6780a4de2c808ddf30d0b
Signed-off-by: David Garcia <david.garcia@canonical.com>
diff --git a/installers/charm/kafka-exporter/metadata.yaml b/installers/charm/kafka-exporter/metadata.yaml
index 1339d27..a70b3b6 100644
--- a/installers/charm/kafka-exporter/metadata.yaml
+++ b/installers/charm/kafka-exporter/metadata.yaml
@@ -19,7 +19,7 @@
 # osm-charmers@lists.launchpad.net
 ##
 
-name: kafka-exporter
+name: kafka-exporter-k8s
 summary: OSM Prometheus Kafka Exporter
 description: |
   A CAAS charm to deploy OSM's Prometheus Kafka Exporter.
@@ -38,7 +38,7 @@
   image:
     type: oci-image
     description: Image of kafka-exporter
-    upstream-source: "bitnami/kafka-exporter:latest"
+    upstream-source: "bitnami/kafka-exporter:1.4.2"
 requires:
   kafka:
     interface: kafka