feat(demo): edge-to-edge insets, editable fields, mock location, and UX polish

[dkhawk]

Description

This PR refactors and polishes the demo application (:places-compose-demo):

Highlights:

1. Edge-to-Edge & System Insets: Updated MainActivity, PlacesAutocompleteMinimalActivity, LandmarkSelectionActivity, and CommonScreen for full edge-to-edge rendering with Scaffold padding and Material 3 TopAppBar styling.
2. Editable Form Fields & Soft Keyboard: Wired bidirectional state updates on address forms so users can edit fields and trigger the virtual keyboard smoothly.
3. Mock Location Fallback: Added a 1-tap "Use Mock Location Instead" fallback to the location permissions screen, enabling rapid emulator/device verification without needing GPS fixes.
4. Address Descriptors & Landmark UX: Added descriptive empty-state guidance and quick-jump Bangalore KTPO demo shortcut for testing Address Descriptors in supported regions.
5. Lint Cleanup: Fixed PluralsCandidate, removed redundant activity labels, and moved legacy drawable assets.

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📚 Stacked PR Chain

#	PR	Description	Base	Status
1	#115	ci/workflow-security-hardening (Workflow permissions & action pinning)	main	✅ CI Passing
2	#116	test/library-coverage-baseline (Test suite reaching 93.8% coverage)	#115	✅ CI Passing
3	#117	build/dependency-modernization (AGP 9.3.2, Gradle 9.5.1, Places 5.3.0)	#116	✅ CI Passing
4	#119	feat/places-usage-attribution (Usage attribution & remove :library)	#117	✅ CI Passing
5	👉 #118	demo/ux-edge-to-edge-polish (Demo UX, edge-to-edge, mock location)	#119	✅ CI Passing

Umbrella PR: #109

[googlemaps-bot]

Code Coverage

Overall Project	86.5%	🍏

There is no coverage information present for the Files changed

[LoyalAbbas]

onEvent(CommonEvent.OnNextMockLocation) updates the state asynchronously in CommonViewModel, but commonViewState.locationLabel is read synchronously in the same click frame before Compose recomposes. As a result, the Snackbar displays the previous location's name (or "Mock Location" on first tap) instead of the newly selected location.

[dkhawk]

Updated! Resolved by decoupling the Snackbar display from synchronous Compose state reads:

1. MergedLocationRepository.nextMockLocation() now returns the selected mock location label directly.
2. CommonViewModel emits the message via snackbarMessage: SharedFlow<String>.
3. CommonScreen collects this flow in a LaunchedEffect(Unit) to show the Snackbar, eliminating the race condition with recomposition and always displaying the newly selected location label immediately.

[LoyalAbbas]

Coroutine Cancellation & RequestQueue Leak in GeocoderRepository.reverseGeocode()

Issues:
Thread/Memory Leak: Volley.newRequestQueue(context) creates a new thread pool (CacheDispatcher + 4 NetworkDispatcher threads) on every single geocoding request and never stops them. RequestQueue should be initialized once as an instance property on GeocoderRepository (e.g. private val requestQueue by lazy { Volley.newRequestQueue(context.applicationContext) }).

Missing Cancellation Hook: Add cont.invokeOnCancellation { stringRequest.cancel() } inside suspendCancellableCoroutine so cancelled coroutines cancel the underlying HTTP request.

[dkhawk]

Updated! Both issues resolved:

1. Initialized RequestQueue once on GeocoderRepository via private val requestQueue by lazy { Volley.newRequestQueue(context.applicationContext) }, avoiding creating thread pools on each geocode request.
2. Added cont.invokeOnCancellation { stringRequest.cancel() } inside suspendCancellableCoroutine so cancelled coroutines properly cancel the underlying Volley request.

[LoyalAbbas]

LGTM