Migrate a lot of classes to Kotlin

app/src/main/java/com/topjohnwu/magisk/utils/XList.kt

@@ -1,5 +1,6 @@
 package com.topjohnwu.magisk.utils
 
+import androidx.collection.SparseArrayCompat
 import androidx.databinding.ObservableList
 import com.skoumal.teanity.extensions.subscribeK
 import com.skoumal.teanity.util.DiffObservableList
@@ -76,4 +77,8 @@ fun <T1> ObservableList<T1>.copyNewInputInto(
         val addedValues = sender?.slice(positionStart until positionEnd).orEmpty()
         target.addAll(addedValues)
     }
-})
+})
+
+operator fun <E> SparseArrayCompat<E>.set(key: Int, value: E) {
+    put(key, value)
+}