github: Switch away from deprecated setup-android (#109)

Signed-off-by: Harsh Shandilya <[email protected]>

.github/workflows/main.yml

@@ -10,8 +10,5 @@ jobs:
     steps:
       - uses: actions/checkout@v1
       - name: setup-android
-        uses: msfjarvis/[email protected]
-        with:
-          # Gradle tasks to run - If you want to run ./gradlew assemble, specify assemble here.
-          gradleTasks: build -x mirai-core:jvmTest
+        run: ./gradlew build -x mirai-core:jvmTest