Zen introduction text updates

- Update color of text/button for legibility
- prevent poorly timed zen update broadcasts from interrupting the
zen footer window animation

Change-Id: I04eaaae80fb0647b0a792023f5ed03ebd9142e04
Fixes: 63916428
Fixes: 63815440
Test: manual
diff --git a/packages/SystemUI/res/values/styles.xml b/packages/SystemUI/res/values/styles.xml
index daed847..7180ea6 100644
--- a/packages/SystemUI/res/values/styles.xml
+++ b/packages/SystemUI/res/values/styles.xml
@@ -220,6 +220,7 @@
 
     <style name="TextAppearance.QS.Introduction">
         <item name="android:textSize">14sp</item>
+        <item name="android:textColor">@color/zen_introduction</item>
     </style>
 
     <style name="TextAppearance.QS.Warning">
@@ -236,7 +237,7 @@
     </style>
 
     <style name="TextAppearance.QS.DetailButton.White">
-        <item name="android:textColor">@color/qs_detail_button_white</item>
+        <item name="android:textColor">@color/zen_introduction</item>
     </style>
 
     <style name="TextAppearance.QS.DetailEmpty">