feat(splunk-on-call-plugin): update changeset + theme style

Signed-off-by: Remi <remi.d45@gmail.com>

.changeset/rude-roses-jam.md

@@ -1,5 +1,6 @@
 ---
-'@backstage/plugin-splunk-on-call': major
+'@backstage/plugin-splunk-on-call': minor
 ---
 
 Updated splunk-on-call plugin to use the REST endpoint (incident creation-acknowledgement-resolution).
+It implies switching from `splunkOnCall.username` annotation to `splunkOnCall.eventsRestEndpoint` annotation, this is a breaking change.

plugins/splunk-on-call/src/components/Escalation/EscalationPolicy.tsx

@@ -37,7 +37,7 @@ const useStyles = makeStyles((theme: Theme) =>
       overflow: 'auto',
     },
     subheader: {
-      backgroundColor: 'white',
+      backgroundColor: theme.palette.background.paper,
     },
     progress: {
       margin: `0 ${theme.spacing(2)}px`,

plugins/splunk-on-call/src/components/Incident/Incidents.tsx

@@ -36,7 +36,7 @@ const useStyles = makeStyles((theme: Theme) =>
       overflow: 'auto',
     },
     subheader: {
-      backgroundColor: 'white',
+      backgroundColor: theme.palette.background.paper,
     },
     progress: {
       margin: `0 ${theme.spacing(2)}px`,