Fix NFC Intent and URL input behavior

SWE will show up for valid NFC intents.
When editing the URL, the voice input icon
shows up only when the url is empty.

Change-Id: If8338a03e4a18bcc78acfdb58bab331bec9af9cd
diff --git a/res/layout/title_bar_nav.xml b/res/layout/title_bar_nav.xml
index aa5032d..375ba84 100644
--- a/res/layout/title_bar_nav.xml
+++ b/res/layout/title_bar_nav.xml
@@ -61,6 +61,7 @@
             android:contentDescription="@string/accessibility_button_stop"
             android:paddingStart="6dp"
             android:paddingEnd="6dp"
+            android:visibility="gone"
             android:src="@drawable/ic_action_stop" />
 
         <com.android.browser.UrlInputView
@@ -90,7 +91,6 @@
             style="@style/NavButton"
             android:layout_width="wrap_content"
             android:contentDescription="@string/accessibility_button_voice"
-            android:paddingEnd="4dip"
             android:src="@drawable/ic_action_microphone_normal"
             android:visibility="gone" />