build: migrate to androidx

* use androidx support library
* update gradle
* update dependencies

Change-Id: Iba7a2734e783a4ce0d5e6459dc33b9036e46d2a5
diff --git a/ring-android/app/src/main/res/layout/frag_sharewith.xml b/ring-android/app/src/main/res/layout/frag_sharewith.xml
index e41b063..7693789 100644
--- a/ring-android/app/src/main/res/layout/frag_sharewith.xml
+++ b/ring-android/app/src/main/res/layout/frag_sharewith.xml
@@ -7,7 +7,7 @@
     android:layout_height="match_parent"
     android:orientation="vertical">
 
-    <android.support.v7.widget.Toolbar
+    <androidx.appcompat.widget.Toolbar
         android:id="@+id/toolbar"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
@@ -52,7 +52,7 @@
 
     </FrameLayout>
 
-    <android.support.v7.widget.RecyclerView
+    <androidx.recyclerview.widget.RecyclerView
         android:id="@+id/shareList"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"