Feature: Add workflow for push/PR checking (#1030)

* Chore: downgrade ndk version

* Fix: fix local.properties load

* Feature: add workflow for push/PR checking

.github/workflows/build-unsigned.yaml

@@ -0,0 +1,24 @@
+name: Build Unsigned
+on: [push, pull_request]
+jobs:
+  BuildUnsigned:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@v2
+        with:
+          submodules: recursive
+      - name: Setup Java
+        uses: actions/setup-java@v1
+        with:
+          java-version: 11
+      - name: Setup Go
+        uses: actions/setup-go@v2
+        with:
+          go-version: 1.16
+      - name: Setup Android SDK
+        uses: android-actions/setup-android@v2
+      - name: Setup Cmake & Ninja
+        uses: lukka/get-cmake@latest
+      - name: Build
+        run: ./gradlew --no-daemon app:assembleRelease