Ensure java updator runs on all active branches (#18408)

* Ensure java updator runs on all active branches

Previously the java updator action would run against only the main branch when
the schedule triggered. This is because the schedule action only tracks the
default branch in a repo. The other branches could be triggered manually with a
workflow dispatch trigger (along with configuring "which branch to run workflow
from"). This old pattern is now replaced with a matrix job which runs the action
across all the active branches. This allows the schedule to update everything
and reduces manual inputs when triggering with workflow dispatch.

* Use elastic/oblt-actions/elastic/active-branches

Rather than use a static list, use the active-branches action to fill in matrix

Author: donoghuc

.github/workflows/bump-java-version.yml

@@ -8,18 +8,35 @@ on:
 
 
 jobs:
+  filter:
+    runs-on: ubuntu-latest
+    timeout-minutes: 1
+    permissions:
+      contents: read
+    outputs:
+      matrix: ${{ steps.generator.outputs.matrix }}
+    steps:
+      - id: generator
+        uses: elastic/oblt-actions/elastic/active-branches@v1
+        with:
+          exclude-branches: "7.17"
+          filter-branches: true
   bump:
     permissions:
       contents: write
       pull-requests: write
     runs-on: ubuntu-latest
+    needs: [filter]
+    strategy:
+      matrix: ${{ fromJson(needs.filter.outputs.matrix) }}
     steps:
       - uses: actions/checkout@v5
-
+        with:
+          ref: ${{ matrix.branch }}
       - uses: elastic/oblt-actions/updatecli/run@v1
         with:
           command: apply --config .ci/updatecli/bump-java-version.yml --values .ci/updatecli/values.d/scm.yml
           version-file: .updatecli-version
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-          LOGSTASH_BRANCH: ${{ github.ref_name }}
+          LOGSTASH_BRANCH: ${{ matrix.branch }}