fix(android): UPnP - add kxml2 to test classpath so DeviceDescriptionTest runs

Android's XmlPullParserFactory is a Stub-throwing class in android.jar
on the JVM unit-test classpath; the probe pattern from dc5b8252 was
silently skipping the test suite, which gives false test-coverage
confidence. kxml2 is the same parser implementation Android uses
internally - service-provider lookup picks it up automatically once
on the test classpath.

The probe + Assumptions.assumeTrue skip removed; tests now run
unconditionally.

testImplementation(libs.kxml2) - 2.3.0, MIT-licensed, ~80KB. No
production code change.

android/app/build.gradle.kts

@@ -187,6 +187,12 @@ dependencies {
     testImplementation(libs.mockk)
     testImplementation(libs.kotlinx.coroutines.test)
     testImplementation(libs.okhttp.mockwebserver)
+    // kxml2 — provides an org.xmlpull.v1 impl on the JVM unit-test
+    // classpath. Android's stock XmlPullParserFactory resolves to the
+    // android.jar Stub on JVM tests; kxml2 is picked up via service-
+    // provider lookup and makes XmlPullParserFactory.newInstance() work
+    // unconditionally so DeviceDescriptionTest runs in CI.
+    testImplementation(libs.kxml2)
     // kotlin.test for assertEquals/assertNull/etc. — version managed by
     // the applied Kotlin plugin so no explicit version pin needed.
     testImplementation(kotlin("test"))