Fix release publish artifact download and per-job Gradle cache keys.

download-artifact accepts one glob pattern, not multiline lists; split platform and Android downloads. Scope Gradle build cache keys per job and use read-only setup-gradle on parallel jobs to avoid cache reservation races.

Co-authored-by: Cursor <cursoragent@cursor.com>

.github/actions/save-gradle-build-cache/action.yml

@@ -1,5 +1,5 @@
 name: Save Gradle build directories
-description: Save module build/ trees after a Gradle build (always runs, even on cache hit)
+description: Save module build/ trees after a Gradle build
 
 inputs:
   primary-key:
@@ -10,6 +10,7 @@ runs:
   using: composite
   steps:
     - uses: actions/cache/save@v5
+      continue-on-error: true
       with:
         key: ${{ inputs.primary-key }}
         path: |