test: add JVM unit and composable integration tests using android-maps-robolectric

[dkhawk]

Summary

This draft PR introduces JVM-based unit and Jetpack Compose integration tests for :maps-compose leveraging the exploratory android-maps-robolectric shadow library (com.google.android.maps.robolectric:shadows:1.0.0).

Note

CI is expected to fail resolution for com.google.android.maps.robolectric:shadows:1.0.0 until the library is published to Maven Central. This PR is intended for early review and exploration of the testing ergonomics and coverage potential.

Test Suites Included

1. CameraPositionStateTest: tests unbound state, map synchronization, instantaneous move(), coroutine animate(), and screen coordinate projection round-trip.
2. MapApplierTest: tests Compose node hierarchy mutation, MarkerNode insertion & MarkerState binding, click events, drag interactions, and circle callbacks.
3. GoogleMapTest: tests full Compose UI lifecycle (<GoogleMap> rendering with markers/circles, marker clicks mutating Compose state, dynamic recomposition additions/removals).

Local Coverage Metrics

Across these 14 fast JVM tests (~7.4s execution time), :maps-compose test coverage reached:

• GoogleMapKt: 69.6%
• CameraPositionState: 69.8%
• MapClickListenersKt: 88.1%
• CircleKt: 78.7%
• Overall :maps-compose: 32.1% instruction coverage (up from 0.0%)

Reviewers: @kikoso, @LoyalAbbas

[github-actions]

Coverage (unit tests)

Compared against a24cc53 on main (#1000).

Module	Line %	Change	Branch %	Change
maps-compose	36.56%	🔺 +36.56	10.32%	🔺 +10.32
maps-compose-utils	2.04%	no change	0.49%	no change
maps-compose-widgets	0.00%	no change	0.00%	no change
TOTAL	27.47%	🔺 +27.05	8.24%	🔺 +8.15

_{Line and branch coverage from unit test reports. History is recorded in coverage/history.csv after each merge to main.}

[googlemaps-bot]

Code Coverage

Overall Project	24.59%	❌

There is no coverage information present for the Files changed