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/res/layout/recent_chapters_controller.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<android.support.v4.widget.SwipeRefreshLayout
+<androidx.swiperefreshlayout.widget.SwipeRefreshLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:id="@+id/swipe_refresh"
@@ -10,7 +10,7 @@
         android:layout_width="match_parent"
         android:layout_height="match_parent">
 
-        <android.support.v7.widget.RecyclerView
+        <androidx.recyclerview.widget.RecyclerView
             android:id="@+id/recycler"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
@@ -26,4 +26,4 @@
 
     </FrameLayout>
 
-</android.support.v4.widget.SwipeRefreshLayout>
+</androidx.swiperefreshlayout.widget.SwipeRefreshLayout>