Added Android CI build

.github/workflows/android.yml

@@ -0,0 +1,44 @@
+name: Android
+
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  build:
+    name: GPXSee
+    runs-on: ubuntu-20.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: set up JDK 1.8
+        uses: actions/setup-java@v1
+        with:
+          java-version: 1.8
+      - name: Setup Android SDK
+        uses: android-actions/setup-android@v2
+      - name: Run sdkmanager update
+        run:  ${ANDROID_HOME}/tools/bin/sdkmanager --update
+      - name: Install android platform, platform-tools, build-tools and ndk
+        run:  ${ANDROID_HOME}/tools/bin/sdkmanager --install "cmdline-tools;latest" "platform-tools" "platforms;android-31" "build-tools;31.0.0" "ndk;22.1.7171670"
+      - name: Cache Qt
+        id: cache-qt
+        uses: actions/cache@v1
+        with:
+          path: ../Qt
+          key: ${{ runner.os }}-QtCache
+      - name: Install Qt
+        uses: jurplel/install-qt-action@v2
+        with:
+          version: '6.3.0'
+          host: 'linux'
+          target: 'android'
+          arch: 'android_arm64_v8a'
+          modules: android
+          install-deps: 'true'
+          cached: ${{ steps.cache-qt.outputs.cache-hit }}
+      - name: Configure build
+        run: $Qt6_DIR/bin/qmake gpxsee.pro
+      - name: Build project
+        run: make -j2