Add windowIsFloating to the volume dialog to fix insets issues.

Fixes: 197245443
Test: manual
Change-Id: I0a073493caec7a0766a388bd291ce10025118456
diff --git a/packages/SystemUI/res/values/styles.xml b/packages/SystemUI/res/values/styles.xml
index d0b2e9f..93d60cc 100644
--- a/packages/SystemUI/res/values/styles.xml
+++ b/packages/SystemUI/res/values/styles.xml
@@ -416,7 +416,9 @@
     </style>
 
     <!-- Overridden by values-television/styles.xml with tv-specific settings -->
-    <style name="volume_dialog_theme" parent="Theme.SystemUI"/>
+    <style name="volume_dialog_theme" parent="Theme.SystemUI">
+        <item name="android:windowIsFloating">true</item>
+    </style>
 
     <style name="Theme.SystemUI.Dialog" parent="@android:style/Theme.DeviceDefault.Light.Dialog" />