minor refactor

app/src/main/java/org/thoughtcrime/securesms/loki/database/SessionJobDatabase.kt

@@ -12,11 +12,11 @@ import org.thoughtcrime.securesms.loki.utilities.*
 class SessionJobDatabase(context: Context, helper: SQLCipherOpenHelper) : Database(context, helper) {
 
     companion object {
-        private val sessionJobTable = "session_job_database"
-        val jobID = "job_id"
-        val jobType = "job_type"
-        val failureCount = "failure_count"
-        val serializedData = "serialized_data"
+        private const val sessionJobTable = "session_job_database"
+        const val jobID = "job_id"
+        const val jobType = "job_type"
+        const val failureCount = "failure_count"
+        const val serializedData = "serialized_data"
         @JvmStatic val createSessionJobTableCommand = "CREATE TABLE $sessionJobTable ($jobID INTEGER PRIMARY KEY, $jobType STRING, $failureCount INTEGER DEFAULT 0, $serializedData TEXT);"
     }