Add GH action for static analysis tool mobsfscan

The action will currently not fail on warnings. That can
be configured after we've went through the warnings and
fixed or suppressed them.

.github/workflows/android-static-analysis.yml

@@ -0,0 +1,27 @@
+---
+name: Android - Static analysis
+on:
+  workflow_dispatch:
+  pull_request:
+    paths:
+      - .github/workflows/android-static-analysis.yml
+      - android/**
+  schedule:
+    # At 06:20 UTC every day.
+    # Notifications for scheduled workflows are sent to the user who last modified the cron
+    # syntax in the workflow file. If you update this you must have notifications for
+    # Github Actions enabled, so these don't go unnoticed.
+    # https://docs.github.com/en/actions/monitoring-and-troubleshooting-workflows/notifications-for-workflow-runs
+    - cron: '20 6 * * *'
+jobs:
+  mobsfscan:
+    name: Code scanning using mobsfscan
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+
+      - name: Scan code
+        uses: MobSF/mobsfscan@main
+        with:
+          args: '--type android android'