Build vulkan+xnnpack AAR (#10301)

Add a flavor option "vulkan+xnnpack" in the workflow

Author: kirklandsign

.github/workflows/android-release-artifacts.yml

@@ -11,6 +11,11 @@ on:
         description: Upload the AAR to maven staging repository
         required: false
         type: boolean
+      flavor:
+        type: choice
+        options:
+          - "xnnpack"
+          - "vulkan+xnnpack"
   schedule:
     - cron: 0 10 * * *
 
@@ -86,6 +91,11 @@ jobs:
           sed -i "s/\(coordinates(\"org.pytorch\", \"executorch-android\", \"\)\([0-9]\+.[0-9]\+.[0-9]\+\)\(\")\)/\1$VERSION\3/" extension/android/executorch_android/build.gradle
         fi
 
+        FLAVOR="${{ inputs.flavor }}"
+        if [[ "$FLAVOR" == "vulkan+xnnpack" ]]; then
+          export EXECUTORCH_BUILD_VULKAN=ON
+        fi
+
         # Build AAR Package
         mkdir aar-out
         export BUILD_AAR_DIR=aar-out