use Shizuku API instead of rish

#10

app/src/main/java/com/bintianqi/owndroid/dpm/ShizukuService.kt

@@ -0,0 +1,46 @@
+package com.bintianqi.owndroid.dpm
+
+import android.os.IBinder
+import android.system.Os
+import com.bintianqi.owndroid.IUserService
+import java.io.BufferedReader
+import java.io.InputStreamReader
+
+var service:IUserService? = null
+
+class ShizukuService: IUserService.Stub() {
+    override fun asBinder(): IBinder {
+        TODO("Not yet implemented")
+    }
+
+    override fun destroy(){ }
+
+    override fun execute(command: String?): String {
+        var result = ""
+        val process:Process
+        try {
+            process = Runtime.getRuntime().exec(command)
+            val exitCode = process.waitFor()
+            if(exitCode!=0){ result+="Error: $exitCode" }
+        }catch(e:Exception){
+            e.printStackTrace()
+            return e.toString()
+        }
+        try {
+            val outputReader = BufferedReader(InputStreamReader(process.inputStream))
+            var outputLine: String
+            while(outputReader.readLine().also {outputLine = it}!=null) { result+="$outputLine\n" }
+            val errorReader = BufferedReader(InputStreamReader(process.errorStream))
+            var errorLine: String
+            while(errorReader.readLine().also {errorLine = it}!=null) { result+="$errorLine\n" }
+        } catch(e: NullPointerException) {
+            e.printStackTrace()
+        }
+        if(result==""){ return "No result" }
+        return result
+    }
+
+    override fun getUid(): String {
+        return Os.getuid().toString()
+    }
+}