Add Kotlin Android build artifacts to gitignore

Author: Jurvis Tan

.gitignore

@@ -21,4 +21,6 @@ swift.abi.json
 swift.swiftdoc
 
 # Ignore ldk_nodeFFI.xcframework files
-/bindings/swift/ldk_nodeFFI.xcframework
+/bindings/swift/ldk_nodeFFI.xcframework
+/bindings/kotlin/ldk-node-android/lib/src/main/jniLibs
+/bindings/kotlin/ldk-node-android/lib/src/main/kotlin/org/lightningdevkit/ldknode/ldk_node.kt