converge onto a single docker image

[prb112]

converge onto a single docker image

Currently we have a debian and a UBI version.
Converge down to one image.

Related #814

[lmsurpre]

I think its mostly unrelated to this one, but I notice that the UBI image prints this warning during startup:

[AUDIT   ] CWWKG0102I: Found conflicting settings for defaultKeyStore instance of keyStore configuration.
  Property password has conflicting values:
    Secure value is set in file:/opt/ol/wlp/usr/servers/fhir-server/configDropins/defaults/keystore.xml.
    Secure value is set in file:/opt/ol/wlp/usr/servers/fhir-server/server.xml.
  Property password will be set to the value defined in file:/opt/ol/wlp/usr/servers/fhir-server/server.xml.