Implement section 2.1 and parts of section 4.1 from the Send Android spec (#901)

* Fix #877 Implement Start page (Empty State) Design

* Update some kotlin and android sdk things, and update to the latest code in vnext

* Begin implementing the card ui which shows after uploading.

* Implement a progress bar.

android/app/src/main/AndroidManifest.xml

@@ -12,6 +12,7 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/AppTheme">
+        <meta-data android:name="android.webkit.WebView.EnableSafeBrowsing" android:value="false" />
         <activity android:name=".MainActivity" android:screenOrientation="portrait">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />