Add an application id suffix

Author: mrober

firebase-sessions/test-app/test-app.gradle.kts

@@ -38,6 +38,7 @@ android {
 
   defaultConfig {
     applicationId = "com.google.firebase.testing.sessions"
+    // applicationIdSuffix = "app3"
     minSdk = minSdkVersion
     targetSdk = targetSdkVersion
     versionCode = 1
@@ -55,6 +56,9 @@ android {
   }
 
   buildTypes {
+    release {
+      signingConfig = signingConfigs["debug"]
+    }
     create("benchmark") {
       initWith(buildTypes["release"])
       signingConfig = signingConfigs["debug"]