fix: Update env name of oidc secret key (#858)

Signed-off-by: Wonyeong Choi <ciwnyg0815@gmail.com>
Co-authored-by: hyein <bogo96@kaist.ac.kr>
Co-authored-by: hyein <bogo96@kaist.ac.kr>

amundsen-kube-helm/templates/helm/templates/deployment-frontend.yaml

@@ -77,7 +77,7 @@ spec:
           - name: OVERWRITE_REDIRECT_URI
             value: {{ .Values.frontEnd.OVERWRITE_REDIRECT_URI }}
           {{- end }}
-          - name: OIDC_SECRET_KEY
+          - name: FLASK_OIDC_SECRET_KEY
             valueFrom:
               secretKeyRef:
                 name: oidc-config