Make H2 the default database used by Gerrit in helm-charts

So far, mysql was configured in the gerrit.config of Gerrit in the
helm-charts. Since most users will probably only use the helm-charts to
install Gerrit >= 2.16, a H2-database would be sufficient for them.

This change makes H2 the database configured by default. This simplifies
the default setup.

Change-Id: I02c9866bced6a97772bff142261caef4829edeab
diff --git a/helm-charts/gerrit-master/values.yaml b/helm-charts/gerrit-master/values.yaml
index a3265a0..962260f 100644
--- a/helm-charts/gerrit-master/values.yaml
+++ b/helm-charts/gerrit-master/values.yaml
@@ -131,16 +131,7 @@
         canonicalWebUrl = http://example.com/
         disableReverseDnsLookup = true
       [database]
-        type = mysql
-        # The name of a Kubernetes service managing the connection to a pod
-        # running the database can be used as a hostname. E.g. if the reviewdb-
-        # chart is used and installed with the name 'db-master', the service
-        # will be named db-master-mysql.
-        hostname = db-master-mysql
-        port = 3306
-        database = reviewdb
-        # To switch off enforced SSL-encrypted communication uncomment:
-        # url = jdbc:mysql://db-master-mysql:3306/reviewdb?nullNamePatternMatchesAll=true&useSSL=false
+        type = h2
       [index]
         type = LUCENE
       [auth]
diff --git a/helm-charts/gerrit-slave/values.yaml b/helm-charts/gerrit-slave/values.yaml
index 96f3d93..a52576e 100644
--- a/helm-charts/gerrit-slave/values.yaml
+++ b/helm-charts/gerrit-slave/values.yaml
@@ -201,16 +201,7 @@
         canonicalWebUrl = http://example.com/
         disableReverseDnsLookup = true
       [database]
-        type = mysql
-        # The name of a Kubernetes service managing the connection to a pod
-        # running the database can be used as a hostname. E.g. if the reviewdb-
-        # chart is used and installed with the name 'db-slave', the service
-        # will be named db-slave-mysql.
-        hostname = db-slave-mysql
-        port = 3306
-        database = reviewdb
-        # To switch off enforced SSL-encrypted communication uncomment:
-        # url = jdbc:mysql://db-slave-mysql:3306/reviewdb?nullNamePatternMatchesAll=true&useSSL=false
+        type = h2
       [index]
         type = LUCENE
       [auth]