App 2.16.3: full screen stays with drop-downs and dialogs

Opening a drop-down or a dialog brought the car's bars back until it
closed: each is a window of its own, and the system shows the bars when
a window without the full-screen flags takes focus.

- The drop-downs (upload frequency, tyre pressure unit, accent colour)
  are now single-choice buttons on the page: no extra window, one tap
  instead of two, full touch targets, the choice in the accent colour.
- Dialogs (About, update, pairing, phone settings, trip reset, date
  picker) are shown unfocusable, given the activity's full-screen
  flags, and only then allowed focus. None of them takes typing, which
  an unfocusable window would block.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QLJfZQZeAKAwSqViTmLzki

app/src/main/res/layout/pane_service.xml

@@ -24,7 +24,7 @@
         <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="vertical" android:padding="24dp" android:background="@drawable/bg_glass" android:layout_marginTop="16dp">
             <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/design_service_timing" android:textAppearance="@style/Text.EV.Eyebrow" />
             <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/label_frequency" android:textAppearance="@style/Text.EV.Body" android:layout_marginTop="20dp" />
-            <Spinner android:id="@+id/interval_spinner" android:layout_width="match_parent" android:layout_height="wrap_content" android:minHeight="72dp" android:layout_marginTop="12dp" android:background="@drawable/bg_input_panel" android:popupBackground="@color/ev_surface_raised" android:contentDescription="@string/label_frequency" android:spinnerMode="dropdown" />
+            <com.google.android.material.chip.ChipGroup android:id="@+id/interval_choices" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="12dp" app:singleSelection="true" app:selectionRequired="true" app:chipSpacingHorizontal="12dp" app:chipSpacingVertical="8dp" />
             <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/hint_frequency" android:textAppearance="@style/Text.EV.Secondary" android:layout_marginTop="12dp" />
             <com.google.android.material.switchmaterial.SwitchMaterial android:id="@+id/boost_switch" android:layout_width="match_parent" android:layout_height="wrap_content" android:minHeight="72dp" android:text="@string/label_boost_low_soc" android:textAppearance="@style/Text.EV.Body" android:paddingTop="8dp" android:paddingBottom="8dp" app:useMaterialThemeColors="true" app:thumbTint="@color/switch_thumb" app:trackTint="@color/switch_track" android:textColor="@color/ev_text_primary" />
             <com.google.android.material.textfield.TextInputLayout android:id="@+id/low_soc_layout" style="@style/Widget.EV.Input" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="12dp" android:hint="@string/label_low_soc_threshold">