Use glean-native in tests

The Glean core native code is now shipped through GeckoView directly
(through its `-omni` packages).
For local tests we need a library matching the host-platform, which is
available in the glean-native package.

app/build.gradle

@@ -583,7 +583,7 @@ dependencies {
 
     // For the initial release of Glean 19, we require consumer applications to
     // depend on a separate library for unit tests. This will be removed in future releases.
-    testImplementation "org.mozilla.telemetry:glean-forUnitTests:${project.ext.glean_version}"
+    testImplementation "org.mozilla.telemetry:glean-native-forUnitTests:${project.ext.glean_version}"
 
     lintChecks project(":mozilla-lint-rules")
 }