ci: re-enable; update java

Signed-off-by: Infi <infi@infi.sh>

.github/workflows/android.yml

@@ -6,8 +6,6 @@ on:
 
 jobs:
   build:
-    if: ${{ false }} # At the moment, we don't want to run this workflow.
-
     runs-on: ubuntu-latest
 
     env:
@@ -18,12 +16,12 @@ jobs:
       RVX_BUILD_FLAVOUR_ID: ${{ vars.RVX_BUILD_FLAVOUR_ID }}
 
     steps:
-      - uses: actions/checkout@v3
-      - name: set up JDK 17
-        uses: actions/setup-java@v3
+      - uses: actions/checkout@v4
+      - name: set up JDK 21
+        uses: actions/setup-java@v4
         with:
-          java-version: '17'
-          distribution: 'temurin'
+          java-version: '21'
+          distribution: 'oracle'
           cache: gradle