Hide soft keyboard on welcome screen launch.

app/src/main/AndroidManifest.xml

@@ -428,7 +428,7 @@
     <activity android:name=".registration.RegistrationNavigationActivity"
               android:launchMode="singleTask"
               android:theme="@style/TextSecure.LightRegistrationTheme"
-              android:windowSoftInputMode="stateUnchanged"
+              android:windowSoftInputMode="stateHidden"
               android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize"/>
 
     <activity android:name=".revealable.ViewOnceMessageActivity"