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/ViewExtensions.kt

@@ -5,7 +5,7 @@ package eu.kanade.tachiyomi.util
 import android.graphics.Color
 import android.graphics.Point
 import android.graphics.Typeface
-import android.support.design.widget.Snackbar
+import com.google.android.material.snackbar.Snackbar
 import android.view.View
 import android.widget.TextView
 import com.amulyakhare.textdrawable.TextDrawable
@@ -28,7 +28,7 @@ fun View.getCoordinates() = Point((left + right) / 2, (top + bottom) / 2)
  */
 inline fun View.snack(message: String, length: Int = Snackbar.LENGTH_LONG, f: Snackbar.() -> Unit): Snackbar {
     val snack = Snackbar.make(this, message, length)
-    val textView: TextView = snack.view.findViewById(android.support.design.R.id.snackbar_text)
+    val textView: TextView = snack.view.findViewById(com.google.android.material.R.id.snackbar_text)
     textView.setTextColor(Color.WHITE)
     snack.f()
     snack.show()