chore(gradle): add root settings for uatu multi-project build

Links :sidecar and :sdk-android under one wrapper. Root build.gradle
provides a clean task that wipes the root build dir.

settings.gradle.kts

@@ -0,0 +1,21 @@
+pluginManagement {
+    repositories {
+        gradlePluginPortal()
+        google()
+        mavenCentral()
+    }
+}
+
+dependencyResolutionManagement {
+    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
+    repositories {
+        google()
+        mavenCentral()
+    }
+}
+
+rootProject.name = "uatu"
+
+include(":sidecar")
+include(":sdk-android")
+project(":sdk-android").projectDir = file("sdk/android")