Voice assistant, vehicle data, and template rendering fixes

Push-to-talk voice control, gated behind experimental settings alongside a new raw vehicle sensor screen. Spotify now shows as partial instead of working since its browse tile rejects Gearslip as a host. Fixed a gap where a live nav app couldn't take a fresh destination without a full reconnect.

gearslip/src/main/res/drawable/navigation_24.xml

@@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+  <path
+      android:fillColor="#FF000000"
+      android:pathData="M12,2L4.5,20.29L5.21,21L12,18L18.79,21L19.5,20.29L12,2Z"/>
+</vector>