Musicbrainz Docker issue fixes

[pingupingu]

• Use the correct oracle jdk (failing to find the correct image)
• Add the correct yarn key instead of using an old version that has expired

[pingupingu]

@yvanzo Should I create a separate request to update the yarn key?

[yvanzo]

Thank you @pingupingu for both reporting bugs and proposing changes. No need to create another request as both issues are now fixed (thus closing this pull request):

• I merged your commit about to update oracle jdk image name (which changed on Jan, 24);
• I fixed Yarn issue with commit 2906242 by refreshing the Yarn Packaging subkey instead.
  Note: Downloading the signing key from the same server as the signed packages bypasses the main purpose of signature check. The fact this method is given in Yarn install docs is yet another issue.
  Edit: Additionally opened Fix APT package installation failure by refreshing keys musicbrainz-server#912