Notification settings, importance and pre-O apps

- Show pre-O settings for the misc channel, should the app still have it
(versus the full channel settings)
- Fix the importance summmary text in various places
- Update the color of the blocked description text
- Fix what fields appear/disappear based on blocked status and importance

Fixes: 38177887
Bug: 38120923
Fixes: 38012300
Fixes: 37923612
Test: manual, with an O app, a pre O app that has channels, and a pre-O
app with no channels
Change-Id: I42965b81b795e8fb427f857c7766fe5480a99f2e

res/values/strings.xml

@@ -6576,6 +6576,12 @@
     <!-- [CHAR LIMIT=100] Notification Importance: blocked importance level description -->
     <string name="notification_importance_blocked">Never show notifications</string>
 
+    <!-- [CHAR LIMIT=100] Notification Importance template for the channel importance summary -->
+    <string name="notification_importance_divider" translatable="false"><xliff:g id="importance_title">%1$s</xliff:g>: <xliff:g id="importance_summary">%2$s</xliff:g></string>
+
+    <!-- Importance title strings for the Importance page. Also the second part of the importance
+     summary on the channel page-->
+
     <!-- [CHAR LIMIT=100] Notification Importance: min importance level description -->
     <string name="notification_importance_min">No sound or visual interruption</string>
 
@@ -6588,6 +6594,9 @@
     <!-- [CHAR LIMIT=100] Notification Importance: high importance level description -->
     <string name="notification_importance_high">Make sound and pop on screen</string>
 
+    <!-- Importance title strings for the Importance page. Also the first part of the importance
+     summary on the channel page-->
+
     <!-- [CHAR LIMIT=100] Notification Importance title: min importance level title -->
     <string name="notification_importance_min_title">Low</string>