test: add comprehensive test suite for places-compose reaching 93.8% coverage

[dkhawk]

Description

This PR establishes a comprehensive unit and Compose UI test suite for the :places-compose library, raising project test coverage from 6.4% to 93.8% before any dependency or demo app changes.

Additions:

1. UnitsTest.kt: Tests Meters value class arithmetic, comparison operators, and extensions (.meters, .m, .km, .feet, .miles, .toFeet, .toMeters, .toKilometers, .toMiles), along with ImperialUnitsConverter vs MetricUnitsConverter threshold formatting. (90.0% coverage)
2. AddressMapperTest.kt: Tests AddressComponentMultiMap multi-type indexing across all AddressComponentType enum variants, longName and shortName string aggregations, and address conversions. (100.0% coverage)
3. PlaceMapperTest.kt: Tests converting Places SDK AddressComponent lists to domain Address models. (100.0% coverage)
4. AutocompleteMapperTest.kt: Tests mapping AutocompletePrediction to AutocompletePlace using MockK. (100.0% coverage)
5. AutocompleteRepositoryTest.kt: Coroutine unit tests verifying PlacesClient delegation. (100.0% coverage)
6. ModelsTest.kt: Tests AutocompletePlace attributes, Area and Landmark spatial relationship string resolution, and distance calculations. (73.7% coverage)
7. AddressDtoTest.kt: Comprehensive unit tests covering reverse geocoding DTO models and Gson serialization. (100.0% coverage)
8. PlacesAutocompleteTextFieldTest.kt: Robolectric Compose UI test suite covering search field rendering, placeholder, keyboard input, prediction list display, place selection, clear button, back navigation button, @Preview composables, dark theme, and expanded states. (94.1% coverage)

Test Harness Configurations:

• Updated PublishingConventionPlugin.kt Jacoco configuration with isIncludeNoLocationClasses = true to capture Robolectric classloader execution.
• Configured places-compose/build.gradle.kts testOptions { unitTests { isReturnDefaultValues = true; isIncludeAndroidResources = true } } and added mockk test dependency.
• Added places-compose/src/debug/AndroidManifest.xml with ComponentActivity and robolectric.properties with sdk=34.

Part of a stacked PR sequence:

• Base PR: ci: pin action SHAs, set permissions, and prevent template injection #115 (ci/workflow-security-hardening)

[googlemaps-bot]

Code Coverage

Overall Project	86.47% -0.05%	🍏
Files changed	87.5%	🍏

File	Coverage
AddressDto.kt	82.68% -0.65%	🍏