car: choose which apps the drawer shows, from a new Apps card on the phone

Short car screens fill up fast, and a phone can offer dozens of car apps
that a driver never opens there. The drawer had no way to leave one out.

The Apps card comes first under Car, with one row per tile, all ticked.
Unticking a row takes the tile out of the drawer at once. It stays pinned
to the nav bar if it was, and Gearslip's own tiles aren't listed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

gearslip/src/main/res/values/strings.xml

@@ -148,6 +148,9 @@
     <string name="cert_kind_self">Self-signed: %1$s</string>
 
     <!-- Car settings on the phone -->
+    <string name="car_apps_sub">Choose which apps appear in the car</string>
+    <string name="car_apps_finding">Finding apps…</string>
+    <string name="car_apps_none">No car apps found</string>
     <string name="car_group_screen">Screen</string>
     <string name="car_group_nav_bar">Nav bar and player</string>
     <string name="car_group_sound">Sound and voice</string>