Add android aar build and connected device test

bindings/bdk-kotlin/android/src/androidTest/assets/logback.xml

@@ -0,0 +1,14 @@
+<configuration>
+  <appender name="logcat" class="ch.qos.logback.classic.android.LogcatAppender">
+    <tagEncoder>
+      <pattern>%logger{12}</pattern>
+    </tagEncoder>
+    <encoder>
+      <pattern>[%-20thread] %msg</pattern>
+    </encoder>
+  </appender>
+
+  <root level="DEBUG">
+    <appender-ref ref="logcat" />
+  </root>
+</configuration>

bindings/bdk-kotlin/android/src/androidTest/kotlin/org/bitcoindevkit/bdk/AndroidLibTest.kt

@@ -0,0 +1,21 @@
+package org.bitcoindevkit.bdk
+
+import android.app.Application
+import android.content.Context.MODE_PRIVATE
+import androidx.test.core.app.ApplicationProvider
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import org.junit.runner.RunWith
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+@RunWith(AndroidJUnit4::class)
+class AndroidLibTest : LibTest() {
+    override fun getTestDataDir(): String {
+        val context = ApplicationProvider.getApplicationContext<Application>()
+        return context.getDir("bdk-test", MODE_PRIVATE).toString()
+    }
+
+}