Create subscriptionsProvider interface

app/src/main/java/org/futo/circles/subscriptions/SubscriptionProvider.kt

+package org.futo.circles.subscriptions
+
+import android.app.Activity
+
+interface SubscriptionProvider {
+
+    fun getManager(
+        activity: Activity,
+        itemPurchaseListener: ItemPurchasedListener
+    ): SubscriptionManager
+
+}
\ No newline at end of file