fix: predictions plugin public init (#3011)

Author: atierian

AmplifyPlugins/Predictions/AWSPredictionsPlugin/AWSPredictionsPlugin.swift

@@ -30,7 +30,7 @@ final public class AWSPredictionsPlugin: PredictionsCategoryPlugin {
         predictionsService.getEscapeHatch(client: key)
     }
 
-    init() {}
+    public init() {}
 }
 
 extension AWSPredictionsPlugin: AmplifyVersionable { }

AmplifyPlugins/Predictions/Tests/AWSPredictionsPluginUnitTests/PredictionsPluginInit.swift

@@ -0,0 +1,24 @@
+//
+// Copyright Amazon.com Inc. or its affiliates.
+// All Rights Reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+import XCTest
+// This import statement needs to stay as it is.
+// Do not add @testable
+import AWSPredictionsPlugin
+
+class PredictionsPluginInitTestCase: XCTest {
+    /// Given: A non @testable import of the `AWSPredictionsPlugin` module
+    /// When:  Initializing the `AWSPredictionsPlugin` class
+    /// Then: The init should not result in a compiler error
+    ///
+    /// - Note: The assertion here is that the plugin's init remains
+    /// public. In the case of a regression (i.e. making the init private / internal),
+    /// the test target will fail to build.
+    func testPublicInitializer() {
+        _ = AWSPredictionsPlugin()
+    }
+}