Add version name to header (#3430)

* Add version name to header

* move comment above declaration

Author: rachaprince

firebase-appdistribution/src/main/java/com/google/firebase/appdistribution/FirebaseAppDistributionTesterApiClient.java

@@ -42,6 +42,8 @@ class FirebaseAppDistributionTesterApiClient {
   private static final String INSTALLATION_AUTH_HEADER = "X-Goog-Firebase-Installations-Auth";
   private static final String X_ANDROID_PACKAGE_HEADER_KEY = "X-Android-Package";
   private static final String X_ANDROID_CERT_HEADER_KEY = "X-Android-Cert";
+  // Format of "X-Client-Version": "{ClientId}/{ClientVersion}"
+  private static final String X_CLIENT_VERSION_HEADER_KEY = "X-Client-Version";
 
   private static final String BUILD_VERSION_JSON_KEY = "buildVersion";
   private static final String DISPLAY_VERSION_JSON_KEY = "displayVersion";
@@ -69,7 +71,7 @@ class FirebaseAppDistributionTesterApiClient {
   }
 
   /**
-   * Fetches and returns the lastest release for the app that the tester has access to, or null if
+   * Fetches and returns the latest release for the app that the tester has access to, or null if
    * the tester doesn't have access to any releases.
    */
   @Nullable
@@ -210,6 +212,8 @@ private HttpsURLConnection openHttpsUrlConnection(
     httpsURLConnection.addRequestProperty(X_ANDROID_PACKAGE_HEADER_KEY, context.getPackageName());
     httpsURLConnection.addRequestProperty(
         X_ANDROID_CERT_HEADER_KEY, getFingerprintHashForPackage(context));
+    httpsURLConnection.addRequestProperty(
+        X_CLIENT_VERSION_HEADER_KEY, String.format("android-sdk/%s", BuildConfig.VERSION_NAME));
     return httpsURLConnection;
   }