android: move to Gradle build

Refs #74812

Change-Id: I2587debb5e4c1584f94370edb36ad87b28fc6c92
diff --git a/ring-android/settings.gradle b/ring-android/settings.gradle
new file mode 100644
index 0000000..e7b4def
--- /dev/null
+++ b/ring-android/settings.gradle
@@ -0,0 +1 @@
+include ':app'