Migrate to AndroidX (#2424)

* Migrate to AndroidX (automatic conversion by Android Studio)

* AndroidX dependency code updates

* Fix source preference reparenting

* fixes the androidx prefererences icon spacing issue

(cherry picked from commit b76a15d960ec2cdf771be16377db0348b66b3179)

* Fix source preference screen heading size/list padding

Co-authored-by: Carlos <cargo8005@gmail.com>

app/src/main/java/eu/kanade/tachiyomi/util/JsoupExtensions.kt

@@ -22,5 +22,5 @@ fun Element.attrOrText(css: String): String {
  * @param html the body of the response. Use only if the body was read before calling this method.
  */
 fun Response.asJsoup(html: String? = null): Document {
-    return Jsoup.parse(html ?: body()!!.string(), request().url().toString())
-}
+    return Jsoup.parse(html ?: body!!.string(), request.url.toString())
+}