Add auto build workflow

[s1204IT]

• Add Action

  • Signing test-keys

• Upgrade targetSdk

[iamr0s]

Good job! 我一直想加一个自动打包的Action，只是最近太懒了

[s1204IT]

But there seems to be a problem with the code and the build fails.

[s1204IT]

> Task :app:compileReleaseKotlin FAILED

e:
file:///home/runner/work/Dhizuku/Dhizuku/app/src/main/java/com/rosan/dhizuku/server/DhizukuUserServiceConnections.kt:51:28
None of the following functions can be called with the arguments supplied:
public open fun startProcess(p0: ComponentName): IBinder! defined in com.rosan.dhizuku.server.DhizukuProcess
invisible_fake open fun startProcess(p0: AppProcess.ProcessParams): Process defined in com.rosan.dhizuku.server.DhizukuProcess

FAILURE: Build failed with an exception.

[s1204IT]

@iamr0s
My request is that if you can resolve the problem that this build does not work, please release a new build (v2.8.1 etc.) that includes new translations.

[iamr0s]

Repaired successfully: https://github.com/iamr0s/Dhizuku/actions

[iamr0s]

以及要注意.gitignore文件，这个r0s.properties文件是我用于本地打包的配置文件。
android test keys需要与它区别开来。