Build Android sample app with GitHub Actions (#810)

Summary:
Getting really pissed off with Travis and this has significantly shorter queue times.

Mind that this probably won't work until the Folly PR is merged.
Pull Request resolved: https://github.com/facebook/flipper/pull/810

Test Plan: CI

Reviewed By: mweststrate

Differential Revision: D19951126

Pulled By: passy

fbshipit-source-id: ed51ad5ec6d4df3a59784dbd31e7c1667593d04f

.github/workflows/android-sample.yml

@@ -0,0 +1,22 @@
+name: Build Sample App
+
+on: [push, pull_request]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: set up JDK 1.8
+      uses: actions/setup-java@v1
+      with:
+        java-version: 1.8
+    - name: Build with Gradle
+      run: ./gradlew :sample:assembleDebug
+    - name: upload artifact
+      uses: actions/upload-artifact@v1
+      with:
+        name: sample-app.apk
+        path: dist/Flipper-mac.zip

.travis.yml

@@ -90,44 +90,3 @@ matrix:
         - IPHONESIMULATOR=$(xcodebuild -showsdks | grep -o "iphonesimulator[0-9]\\+\\.[0-9]\\+$")
         - travis_wait xcodebuild build -workspace SampleSwift.xcworkspace -scheme SampleSwift -sdk $IPHONESIMULATOR -quiet > ./build.log
         - tail -100 ./build.log
-
-    - language: android
-      os: linux
-      dist: trusty
-      android:
-        components:
-          - tools
-          - platform-tools
-          - build-tools-27.0.3
-          - android-27
-          - extra-google-google_play_services
-          - extra-google-m2repository
-          - extra-android-m2repository
-          - addon-google_apis-google-27
-
-        licenses:
-          - android-sdk-preview-license-.+
-          - android-sdk-license-.+
-          - google-gdk-license-.+
-
-      cache:
-        directories:
-          - $HOME/.gradle/wrapper
-          - $HOME/.gradle/caches
-          - android/third-party/external
-
-      before_install:
-        - yes | sdkmanager "platforms;android-27"
-        - echo "y" | sdkmanager "cmake;3.6.4111459"
-        - wget -q https://dl.google.com/android/repository/android-ndk-r20-linux-x86_64.zip
-        - mkdir -p temp-android-ndk
-        - mv ./android-ndk-r20-linux-x86_64.zip temp-android-ndk
-        - cd temp-android-ndk
-        - unzip -q android-ndk-r20-linux-x86_64.zip
-        - export ANDROID_NDK_HOME=`pwd`/android-ndk-r20
-        - export PATH=${PATH}:${ANDROID_NDK_HOME}
-        - cd ../
-      script:
-        - ./gradlew :sample:assembleDebug
-        - ./gradlew :android:testDebugUnitTest :sample:testDebugUnitTest
-        - ./gradlew :tutorial:assembleDebug